2002 Vol.15(2)
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2002, 16(2).
Abstract:
The dymaic property of piezoelectric micro displacement actuator (PMDA) is analyzed, especially the mechanical characteristic, lag phase property and hysteresis phenomenon. The influence factors of static and dymanic mechanical characteristics and the lag phase property are analyzd systematically. Three main influence factors of lag phase property are discovered. With comparison to mechanical Coulomb friction, a generalized model of onlinear hysteresis of PMDA is advanced, based on the essential analysis of nonlinear phenomenon. Finally the application of PMDA in error compensation control system of boring is introduced. A good compensation result is achieved.
The dymaic property of piezoelectric micro displacement actuator (PMDA) is analyzed, especially the mechanical characteristic, lag phase property and hysteresis phenomenon. The influence factors of static and dymanic mechanical characteristics and the lag phase property are analyzd systematically. Three main influence factors of lag phase property are discovered. With comparison to mechanical Coulomb friction, a generalized model of onlinear hysteresis of PMDA is advanced, based on the essential analysis of nonlinear phenomenon. Finally the application of PMDA in error compensation control system of boring is introduced. A good compensation result is achieved.
2002, 16(2).
Abstract:
An adaptive learning control scheme intended to the on-line optimization of sculptured surface cutting process is presented. The scheme uses a back-propagation neural network to learn the relationships between process inputs and process states. The cutting parameters of the process model are optimized through a genetic algorithms(GA). The capacity of the proposed scheme for determining optimum process inputs under a variety of process conditions and optimization strategies is evaluated on the basis of milling of a sculptured surface using a ball-end mill. The experimental results show that the neural network could model the cutting process efficiently, and the cutting conditions such as spindle speed could be regulated for achieving high efficiency and high quality. Therefore the proposed approach can be well applied to the manufacturing of dies and molds.
An adaptive learning control scheme intended to the on-line optimization of sculptured surface cutting process is presented. The scheme uses a back-propagation neural network to learn the relationships between process inputs and process states. The cutting parameters of the process model are optimized through a genetic algorithms(GA). The capacity of the proposed scheme for determining optimum process inputs under a variety of process conditions and optimization strategies is evaluated on the basis of milling of a sculptured surface using a ball-end mill. The experimental results show that the neural network could model the cutting process efficiently, and the cutting conditions such as spindle speed could be regulated for achieving high efficiency and high quality. Therefore the proposed approach can be well applied to the manufacturing of dies and molds.
2002, 16(2).
Abstract:
Research work on plug-and-play open architecture and object-oriented mechatronic system integration is described. The original controllers of two popular industrial robot manipulators Puma 560 and IBM 7575 are completely retrofitted and integrated with a conveyor system to form a robot workcell. This robot workcell can be programmed to run under the Ch language environment. The outline of the Ch language, and the retrofitting strategy of the robot workcell will be described. A sample application program for simulated assembly operations of this robot workcell will be presented to demonstrate the underlying principles of open architecture integration of mechatronic systems under the programming paradigm of the Ch language environment.
Research work on plug-and-play open architecture and object-oriented mechatronic system integration is described. The original controllers of two popular industrial robot manipulators Puma 560 and IBM 7575 are completely retrofitted and integrated with a conveyor system to form a robot workcell. This robot workcell can be programmed to run under the Ch language environment. The outline of the Ch language, and the retrofitting strategy of the robot workcell will be described. A sample application program for simulated assembly operations of this robot workcell will be presented to demonstrate the underlying principles of open architecture integration of mechatronic systems under the programming paradigm of the Ch language environment.
2002, 16(2).
Abstract:
The profile error evaluation of complex curves and surfaces expressed in parametric form is considered. The linear error model is established on the base of two hypotheses firstly. Then the profile error evaluation is converted into one of these optimal formulations：MINIMAX, MAXMIN and MINIDEX problems, which are easier to be solved than the initial form. To each one of them, geometric condition and algebraic condition are presented to arbitrate whether the ideal element reaches to the optimal position. Exchange algorithm is proven highly effective in searching for solutions to these optimization problems. At last some key problems in tolerance evaluation of freeform surfaces and curves in B spline method are discussed.
The profile error evaluation of complex curves and surfaces expressed in parametric form is considered. The linear error model is established on the base of two hypotheses firstly. Then the profile error evaluation is converted into one of these optimal formulations：MINIMAX, MAXMIN and MINIDEX problems, which are easier to be solved than the initial form. To each one of them, geometric condition and algebraic condition are presented to arbitrate whether the ideal element reaches to the optimal position. Exchange algorithm is proven highly effective in searching for solutions to these optimization problems. At last some key problems in tolerance evaluation of freeform surfaces and curves in B spline method are discussed.
2002, 16(2).
Abstract:
The special subject "research on life prediction technology of important in-service pressure vessels" mainly analyzes the failure mechanism of large-sized important and critical in-service pressure vessels under the action of workin medium and investigates safety assessment and life prediction technology with a view to enhance the operation reliability of in-service pressure vessels in China. Based on a series of accident investigation and test & measuring research, the cause of cracking of catalytic regenerator is analyzed and the in-line non-destructive examination method and failure prevention measures for the cracking of catalytic regenerator are proposed.
The special subject "research on life prediction technology of important in-service pressure vessels" mainly analyzes the failure mechanism of large-sized important and critical in-service pressure vessels under the action of workin medium and investigates safety assessment and life prediction technology with a view to enhance the operation reliability of in-service pressure vessels in China. Based on a series of accident investigation and test & measuring research, the cause of cracking of catalytic regenerator is analyzed and the in-line non-destructive examination method and failure prevention measures for the cracking of catalytic regenerator are proposed.
2002, 16(2).
Abstract:
A robotic endoscope is mainly composed of a tactile array sensor, soft mobile mechanism for earthworm locomotion and turning mechanism based on shape memory effect. The tactile array sensor can provide the information about magnitude and orientation of interacting forces between the robotic endoscope and the wall of gastrointestinal tracts. The soft mobile mechanism contacts gastrointestinal tracts with air-in inflatable balloons, so it has better soft and non-invasive properties. The turning mechanism can be actively bent by shape memory alloy components and conform to the complex shape of gastrointestinal tracts. The working principle of robotic endoscope is dealt with.
A robotic endoscope is mainly composed of a tactile array sensor, soft mobile mechanism for earthworm locomotion and turning mechanism based on shape memory effect. The tactile array sensor can provide the information about magnitude and orientation of interacting forces between the robotic endoscope and the wall of gastrointestinal tracts. The soft mobile mechanism contacts gastrointestinal tracts with air-in inflatable balloons, so it has better soft and non-invasive properties. The turning mechanism can be actively bent by shape memory alloy components and conform to the complex shape of gastrointestinal tracts. The working principle of robotic endoscope is dealt with.
2002, 16(2).
Abstract:
The sol-gel process, using aqueous solutions is used for dip coating onto subestrates of 316L stainless steel. A suitable coating of LiCoO2 is achieved by varying the thickness and heat treating at 650℃ for 3h. Thermal analysis, X-ray diffraction analysis and SEM are carried out to characterize the microstructure of the coatings. The results show that the coating tranforms from an amorphous gel to crystalline phases above 350℃, and show a porous stucture. The phase transition mechanism is discussed.
The sol-gel process, using aqueous solutions is used for dip coating onto subestrates of 316L stainless steel. A suitable coating of LiCoO2 is achieved by varying the thickness and heat treating at 650℃ for 3h. Thermal analysis, X-ray diffraction analysis and SEM are carried out to characterize the microstructure of the coatings. The results show that the coating tranforms from an amorphous gel to crystalline phases above 350℃, and show a porous stucture. The phase transition mechanism is discussed.
2002, 16(2).
Abstract:
Developing CNC measuing method on the base of coordinate machine can make the best of the hardware resource of CNC system and realize the integration of CAD/CAM/CAT. Based on the evenly spaced parallel planes scanning, a new adaptive digitizing approach for freeform surface namely arc length extrapolation is put forward. By this way, the digitizing approach can be added to the CNC system, while the system's hardware and software are not changed.
Developing CNC measuing method on the base of coordinate machine can make the best of the hardware resource of CNC system and realize the integration of CAD/CAM/CAT. Based on the evenly spaced parallel planes scanning, a new adaptive digitizing approach for freeform surface namely arc length extrapolation is put forward. By this way, the digitizing approach can be added to the CNC system, while the system's hardware and software are not changed.
2002, 16(2).
Abstract:
An intelligent welding robot for spherical tank's all-position multi-layer welds is developed. Based on the dynamics analyzing and simulation tesing, a flexible mangetic wheel mechanism is created as the robot's walking carriage. It makes the robto directly attracted to the surface of the spherical tank so as to realize the all-position walking and welding without rail. At the same time, a CCD real-time tracing system is developed for the robot to repeatedly trace the all-position and multi-layer seams. The welding tests show that the welding robot can make the all-position and multi-layer welds with high tracing accuracy, excellent quality and reliable behavior, and it can be applied for practical production.
An intelligent welding robot for spherical tank's all-position multi-layer welds is developed. Based on the dynamics analyzing and simulation tesing, a flexible mangetic wheel mechanism is created as the robot's walking carriage. It makes the robto directly attracted to the surface of the spherical tank so as to realize the all-position walking and welding without rail. At the same time, a CCD real-time tracing system is developed for the robot to repeatedly trace the all-position and multi-layer seams. The welding tests show that the welding robot can make the all-position and multi-layer welds with high tracing accuracy, excellent quality and reliable behavior, and it can be applied for practical production.
2002, 16(2).
Abstract:
Based on the analysis of the pin-hole-output mechanism in the cycloid drive , a more accurate force analysis method is provided, in which the manufacture error is considered, by which the contact force between pin and pin-hole can be calculated more accurately in the whole driving process.
Based on the analysis of the pin-hole-output mechanism in the cycloid drive , a more accurate force analysis method is provided, in which the manufacture error is considered, by which the contact force between pin and pin-hole can be calculated more accurately in the whole driving process.
2002, 16(2).
Abstract:
A surface roughness model utilizing regression analysis method is developed for predicting roughness of ultraprecision machined surface with a single crystal diamond tool. The effects of the main variables,such as cutting speed,feed,and depth of cut on surface roughness are also analyzed in diamond turning aluminum alloy. In order to predict and control the surface roughness before ultraprecision machining, constrained variable metric method is used to select the optimum cutting conditions during process planning. A lot of experimental results show that the model can predict the surface roughness effectively under a certain cutting conditions.
A surface roughness model utilizing regression analysis method is developed for predicting roughness of ultraprecision machined surface with a single crystal diamond tool. The effects of the main variables,such as cutting speed,feed,and depth of cut on surface roughness are also analyzed in diamond turning aluminum alloy. In order to predict and control the surface roughness before ultraprecision machining, constrained variable metric method is used to select the optimum cutting conditions during process planning. A lot of experimental results show that the model can predict the surface roughness effectively under a certain cutting conditions.
2002, 16(2).
Abstract:
Car styling technique based on a new theoretical model of automotive aerodynamics is introduced, which is proved to be feasible and effective by wind tunnel tests. Development of a multi-module software system from this Technique, including modules of knowledge processing, referential styerential styling and ANN aesthetic evaluation etc, capable of assisting car styling works in an intelligent way, is also presented and discussed.
Car styling technique based on a new theoretical model of automotive aerodynamics is introduced, which is proved to be feasible and effective by wind tunnel tests. Development of a multi-module software system from this Technique, including modules of knowledge processing, referential styerential styling and ANN aesthetic evaluation etc, capable of assisting car styling works in an intelligent way, is also presented and discussed.
2002, 16(2).
Abstract:
A numerical model on stress assessment of a defective elliptic gathering tube used in the heat recovery boiler of a pyrolyzer is built up. The effect of local defects on the carrying capacity of the tube is analyzed by using the MSC/NASTRAN finite element code, and the critical size of defects is obtained. Then, two numerical models of damaged tube with local and integral reinforcements, respectively, are also calculated. Stress classification and assessments are provided by applying the ASME and JB4732—1995 standard. Some guidance and suggestions about the tube reinforcements and the prediction of the remaining life of the structure for engineering practice are discussed.
A numerical model on stress assessment of a defective elliptic gathering tube used in the heat recovery boiler of a pyrolyzer is built up. The effect of local defects on the carrying capacity of the tube is analyzed by using the MSC/NASTRAN finite element code, and the critical size of defects is obtained. Then, two numerical models of damaged tube with local and integral reinforcements, respectively, are also calculated. Stress classification and assessments are provided by applying the ASME and JB4732—1995 standard. Some guidance and suggestions about the tube reinforcements and the prediction of the remaining life of the structure for engineering practice are discussed.
2002, 16(2).
Abstract:
Fault detection and diagnosis for pneumatic system of automatic production line are studied. An expert system using fuzzy-neural network and pneumatic circuit fault diagnosis instrument are designed. The mathematical model of various pneumatic faults and experimental device are built. In the end, some experiments are done, which shows that the expert system using fuzzy-neural network can diagnose fast and truly fault of pneumatic circuit.
Fault detection and diagnosis for pneumatic system of automatic production line are studied. An expert system using fuzzy-neural network and pneumatic circuit fault diagnosis instrument are designed. The mathematical model of various pneumatic faults and experimental device are built. In the end, some experiments are done, which shows that the expert system using fuzzy-neural network can diagnose fast and truly fault of pneumatic circuit.
2002, 16(2).
Abstract:
It is known that manufacture of hypoid gears is difficult and complicated, the reason lies on the limitation of traditional mechanical machine tools. With the development of NC machine tools, there should be new ways of cutting this kind of gear. Therefore, an idea to generate gears with conjugating tooth surfaces is proposed, based on the “flexibility” characteristic of NC that means various motions, in a sense, can be performed arbitrarily on NC machine tools. Using this method, the direction of the contact path on tooth surfaces can be controlled, and also, theoretically, the generated tooth surfaces can transmit motion at specific transmission ratio curve.
It is known that manufacture of hypoid gears is difficult and complicated, the reason lies on the limitation of traditional mechanical machine tools. With the development of NC machine tools, there should be new ways of cutting this kind of gear. Therefore, an idea to generate gears with conjugating tooth surfaces is proposed, based on the “flexibility” characteristic of NC that means various motions, in a sense, can be performed arbitrarily on NC machine tools. Using this method, the direction of the contact path on tooth surfaces can be controlled, and also, theoretically, the generated tooth surfaces can transmit motion at specific transmission ratio curve.
2002, 16(2).
Abstract:
Two new fuzzy controllers are designed, one's control rules are adjusted by error integral, another are with feedforward of error integral. If only the control rules and parameters are selected felictiously, the static errors of the system will be eliminated. The test results show that the controllers can assuredly inprove static performances of the controlled system.
Two new fuzzy controllers are designed, one's control rules are adjusted by error integral, another are with feedforward of error integral. If only the control rules and parameters are selected felictiously, the static errors of the system will be eliminated. The test results show that the controllers can assuredly inprove static performances of the controlled system.
2002, 16(2).
Abstract:
A new concept called intelligent virtual control (IVC), which can be driven by measuring functions, is put forward. This small “intelligent measurement instrument unit (IMIU)”, carrying with functions of instrument, consists of different types of intelligent virtual instrument (IVI) through individual components together as building blocks and can be displayed directly on the computer screen. This is a new concept of measuring instrument, and also an important breakthrough after virtual instrument (VI). Virtual control makes instrument resources obtain further exploitation. It brings about a fundamental change to the design and manufacturing mode. The instrument therefore, can not only be produced directly inside a PC, but the product is involved in the “green product” system. So far, all the present digital instruments will grow to be replaced by intelligent control with green characteristics.
A new concept called intelligent virtual control (IVC), which can be driven by measuring functions, is put forward. This small “intelligent measurement instrument unit (IMIU)”, carrying with functions of instrument, consists of different types of intelligent virtual instrument (IVI) through individual components together as building blocks and can be displayed directly on the computer screen. This is a new concept of measuring instrument, and also an important breakthrough after virtual instrument (VI). Virtual control makes instrument resources obtain further exploitation. It brings about a fundamental change to the design and manufacturing mode. The instrument therefore, can not only be produced directly inside a PC, but the product is involved in the “green product” system. So far, all the present digital instruments will grow to be replaced by intelligent control with green characteristics.
2002, 16(2).
Abstract:
Micro electro discharge machining (micro EDM) is a feasible way to manufacture micro structures and has potential application in advanced in dustrial fields. For the realzation of micro EDM, it is necessary to pay careful attention to its equipment design and the development of process techniques. The present status of research and develpoment of micro EDM equipment and process techniques is overviewed. A micro electro discharge machine incorporated with an inchworm type of micro feed mechanism is introduced, and a micro electro discharge machine for drilling micro holes suitable to industrial use is also introduced. Some of the machining experiments carried out on the micro EDM prototypes are shown and the feasibilty of the micro EDM techology to practical use is discussed.
Micro electro discharge machining (micro EDM) is a feasible way to manufacture micro structures and has potential application in advanced in dustrial fields. For the realzation of micro EDM, it is necessary to pay careful attention to its equipment design and the development of process techniques. The present status of research and develpoment of micro EDM equipment and process techniques is overviewed. A micro electro discharge machine incorporated with an inchworm type of micro feed mechanism is introduced, and a micro electro discharge machine for drilling micro holes suitable to industrial use is also introduced. Some of the machining experiments carried out on the micro EDM prototypes are shown and the feasibilty of the micro EDM techology to practical use is discussed.
2002, 16(2).
Abstract:
Aiming at the new characteristic of water hydraulic system, a kind of hydrostatic bearing with a concentric gap damper is introduced. The lubricative film thickness of the hydrostatic bearing possesses inflexibility and the loading capacity is just determined by the geometrical dimension of the piston-slipper subassembly and has no relation with system pressure, viscosity and temperature of water and speed of rotor. Theoretical analyses and the verification of scheme done at the test rig show that the hydrostatic bearing with a concentric gap damper is especially fit for water hydraulic components.
Aiming at the new characteristic of water hydraulic system, a kind of hydrostatic bearing with a concentric gap damper is introduced. The lubricative film thickness of the hydrostatic bearing possesses inflexibility and the loading capacity is just determined by the geometrical dimension of the piston-slipper subassembly and has no relation with system pressure, viscosity and temperature of water and speed of rotor. Theoretical analyses and the verification of scheme done at the test rig show that the hydrostatic bearing with a concentric gap damper is especially fit for water hydraulic components.
2002, 16(2).
Abstract:
Several kinds of special alloys are produced on the surfaces of iron and steels by using double glow surface alloying technology. Surface Ni-Cr-Mo-Nb alloy, surface precipitaion hardening high speed steel and surface precipitation hardening stainless steel are introduced.
Several kinds of special alloys are produced on the surfaces of iron and steels by using double glow surface alloying technology. Surface Ni-Cr-Mo-Nb alloy, surface precipitaion hardening high speed steel and surface precipitation hardening stainless steel are introduced.
2002, 16(2).
Abstract:
The resonance sound radiation from submerged infinite elastic cylindrical shell, excited by internal harmonic line force, is investigated. The shell radiation power is presented in terms of resonant modal radition derived from resonance radiation theory (RRT). The resonance radiation formulae are derived from classical ravleigh normal mode solution, which are useful for understanding the mechanism of sound radiation from submerged shells. As an example, numerical calculation of a thin steel cylindrical shell is done by using these two methods. It seems that the results of RRT solutions are in good agreement with that of Rayleigh normal mode solutions.
The resonance sound radiation from submerged infinite elastic cylindrical shell, excited by internal harmonic line force, is investigated. The shell radiation power is presented in terms of resonant modal radition derived from resonance radiation theory (RRT). The resonance radiation formulae are derived from classical ravleigh normal mode solution, which are useful for understanding the mechanism of sound radiation from submerged shells. As an example, numerical calculation of a thin steel cylindrical shell is done by using these two methods. It seems that the results of RRT solutions are in good agreement with that of Rayleigh normal mode solutions.
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