During surgical interventions, the temperature generated during cortical bone drilling can affect the activity of bone material, which may lead to necrosis. In this paper, with the purpose of reducing the temperature ...
During surgical interventions, the temperature generated during cortical bone drilling can affect the activity of bone material, which may lead to necrosis. In this paper, with the purpose of reducing the temperature during cortical bone drilling, the influence of the parameters of medical drill were analyzed. The finite element model of the drilling process was established based on the parametric design of the dril. The relationship between the drill bit diameter, the point angle, and the helix angle to the drilling temperature was studied by the center composite experiment. The results showed that the drilling temperature is increased with the increase of drill diameter, vertex angle and helix angle in the range of certain research.
According to the problem that the selection of traditional PID control parameters is too complicated in evaporator of Organic Rankine Cycle system(ORC),an evaporator PID controller based on BP neural netw ork optimiza...
详细信息
According to the problem that the selection of traditional PID control parameters is too complicated in evaporator of Organic Rankine Cycle system(ORC),an evaporator PID controller based on BP neural netw ork optimization is designed. Based on the control theory,the model of ORC evaporator is set up. The BP algorithm is used to control the Kp,Kiand Kdparameters of the evaporator PID controller,so that the evaporator temperature can reach the optimal state quickly and steadily. The M ATLAB softw are is used to simulate the traditional PID controller and the BP neural netw ork PID controller. The experimental results show that the Kp,Kiand Kdparameters of the BP neural netw ork PID controller are 0. 5677,0. 2970,and 0. 1353,***,the evaporator PID controller based on BP neural netw ork optimization not only satisfies the requirements of the system performance,but also has better control parameters than the traditional PID controller.
By the experiment modal research for unit structure, the natural frequency and mass of US by means of experimental modal analysis is explored. Experimental modal analysis on US was applied to achieve optimal US simult...
详细信息
By the experiment modal research for unit structure, the natural frequency and mass of US by means of experimental modal analysis is explored. Experimental modal analysis on US was applied to achieve optimal US simultaneously to satisfy multiple conflicting performance requirements of mass and natural frequency of US. Then the structural parameters of US were optimized to increase natural frequencies and reduce mass. Experimental modal analysis is an efficient technique to accurately identify the dynamic behavior of a structure and provides modal parameters, such as natural frequencies and mode shapes.
The parallel manipulator has some advantages of high accuracy,high speed and high stiffness *** makes up for the shortcomings of serial *** the parallel mechanism becomes a potential motion platform with high speed an...
详细信息
ISBN:
(纸本)9781509001668
The parallel manipulator has some advantages of high accuracy,high speed and high stiffness *** makes up for the shortcomings of serial *** the parallel mechanism becomes a potential motion platform with high speed and high *** poles parallel robot improves these defects of more singularity,poor load capacity and low stiffness which exist in workspace of the classic plane five poles parallel *** and forward kinematic models are established based on the structure of the *** influence of foundation beds' location error,driving angle error and rod processing error on control accuracy is systematically *** theoretical foundation has been provided for realizing the optimal design of the robot and control in high accuracy.
In order to improve the flexibility of the pickup manipulator and solve the problem of picking up small sports balls in training ground such as golfing, tennis, and table tennis, a 5-DOF pickup manipulator structure i...
In order to improve the flexibility of the pickup manipulator and solve the problem of picking up small sports balls in training ground such as golfing, tennis, and table tennis, a 5-DOF pickup manipulator structure is designed. According to the pickup task requirements of the manipulator, through theoretical calculations, the 86HS series stepping motor is selected as the driving motors of the front end joints. Based on this, the stepping motor controlsystem is designed to realize the closed-loop control of the manipulator. Then the manipulator model is built using D-H method, the inverse kinematics solution is calculated, and the analysis of kinematic theory is conducted. Finally, the targeted pickup point is selected to carry out case simulation analysis of the manipulator, the motion law of the manipulator is verified to be reasonable and the task of picking up small sports balls is completed.
Objective To investigate the effect of fibre periodontal splint restoration on mandibular anterior teeth displacement and periodontal membrane stress. Methods Micro-CT scanning technology, combined with Mimics, Geomag...
Objective To investigate the effect of fibre periodontal splint restoration on mandibular anterior teeth displacement and periodontal membrane stress. Methods Micro-CT scanning technology, combined with Mimics, Geomagic studio and SolidWorks were used to establish 3D dental models of mandibles with teeth and the models fibre periodontal splint restoration; the models of mandibular anterior loosen teeth was constructed under 30 degree oblique 25N loading on the labial and lingual sides respectively. Then, under different angles force with or without the splint, the analysis on dental mechanical state are given. Results It was determined that the sum of the maximal displacement of the loosen tooth model at the lingual and labial sides was 1 mm, which represented the degree I loosen model. After splint repair on the model, the maximal displacement of loosen tooth decreased 47.7%, 85.1% and 85.8% at 0 degree, 15 degree and 30 degree forces respectively, and the maximum stress of periodontal membrane decreased by 22.3%, 61.2% and 74.9%. Conclusion Fixation of loosen teeth through fibre periodontal splints can reduce the maximum stress of periodontal membrane and the maximal displacement of the teeth, thus ensuring the stability of loosen tooth.
P91 heat-resistant steel is widely used in the high temperature of piping components of thermal power plants and nuclear power plants. In these conditions, the typical failure of P91 is mainly caused by creep at low s...
详细信息
In this paper,a novel steamer feeding robot is designed and *** compared to the currently used steamer feeding robot,the feeding process of the proposed robot is continuous,and this way will greatly improve the effici...
详细信息
ISBN:
(纸本)9781138065833
In this paper,a novel steamer feeding robot is designed and *** compared to the currently used steamer feeding robot,the feeding process of the proposed robot is continuous,and this way will greatly improve the efficiency and quality of the feeding ***,the mechanical structure and kinematics of the novel steamer feeding robot are introduced and *** then,the controlsystem of the robot is ***,experiment evidences are given to prove the efficiently of brewing by using this robot.
The identification model of milling force coefficient is established using the model of dynamic milling force and the regression analysis of the milling force experiment data. On the basis of the existing milling forc...
详细信息
The identification model of milling force coefficient is established using the model of dynamic milling force and the regression analysis of the milling force experiment data. On the basis of the existing milling force model, by simplifying and calculation, it can get the relational expression between milling force coefficient and average value of the milling force. Arranging the milling force experiment and measuring average milling force, the experiment results of milling force coefficient can be calculated. Then, the polynomial expression of identification model of milling force coefficient is established, and its coefficient values can be got by regression analysis. Finally, the accuracy and applicability of the identification model is verified by experiment. The experimental results show that the prediction results of the model are accurate and reliable, and can meet different processing conditions, provide the theoretical basis and reference for the further study of milling process and optimization.
Reconfigurability of the modular robot is becoming curial to be a high flexibility for the wide varieties of tasks and environments. In this paper, a novel self-reconfigurable modular robot called M 2 sbot is designed...
详细信息
ISBN:
(纸本)9781509023974
Reconfigurability of the modular robot is becoming curial to be a high flexibility for the wide varieties of tasks and environments. In this paper, a novel self-reconfigurable modular robot called M 2 sbot is designed, which has the approximate cuboid shaping structure. The unit model is with one active and five passive connection surfaces, compact structure and flexible motion. It is characterized by using the unique hook-claw docking mechanism as the docking part of the neighbor modular. And the responding controlsystem based on STM32F103VET6 is also implemented. The forward kinematic equations of the chain robot are established, and then the dynamic equation is generated by the recursive Newton-Euler method based on the global matrix description. Finally, the calculation and simulation analysis of the six-module configuration with two branches demonstrates the feasibility of the proposed method in the generation of motion equation.
暂无评论