猎豹汽车总装车间控制系统的开发与应用

结合湖南长丰汽车公司总装车间控制系统的开发与实施，介绍了湖南长丰汽车公司总装车间控制系统的设计、硬件组成、软件实现以及上位机、触摸显示屏等内容。现场应用表明，该系统完全满足湖南长丰汽车公司总装车间的控制要求，有一定的先进性，值得推广应用。     

空气预热器管箱制作中焊接变形的控制

介绍了管式空气预热器的结构特点，对制作中焊接变形产生的原因进行了分析，并对控制焊接变形措施作了详尽的叙述。     

绷丝机上丝装置的自动控制

介绍了绷丝机上丝装置的一种自动控制系统，实践证明它结构简单、准确率高。     

数控切割中齿条质量的控制方法

针对齿轨车用齿条在生产中存在的问题，通过对数控程序的改进，利用齿条自身的特点，解决了齿条在生产中无法保证质量的问题，并通过新IH程序的比较，证明改进后的工艺方法更经济适用。     

电伺服数控转塔冲床的PMC轴应用

对MT-200型电伺服数控转塔冲床的伺服主传动结构形式进行了简述,详细说明如何应用FANUC 18i数控系统的PMC轴控制功能,编制PMC程序,处理相关信号,实现A轴冲压功能。     

DESIGN AND CONTROL OF AN ULTRAPRECISION STAGE USED IN GRATING TILING

In petawatt laser system, the gratings used to compose pulse compressor are very large in size which can be only acquired currently by arraying small aperture gratings to form a large one instead, an approach referred to as grating tiling. Theory and experiments have demonstrated that the coherent addition of multiple small gratings to form a larger grating is viable, the key technology of which is to control the relative position and orientation of each grating with high precision. According to the main factors that affect the performance of the grating tiling, a 5-DOF ultraprecision stage is developed for the grating tiling experiment. The mechanism is formed by serial structures. The motion of the mechanism is guided by flexure hinges and driven by piezoelectric actuators and the movement resolution of which can achieve nanometer level. To keep the stability of the mechanism, capacitive position sensors with nanometer accuracy are fixed on it to provide feedback signals with which to realize closed-loop control, thus the positioning precision of the mechanism is within several nanometers range through voltage control and digital PID algorithm. Results of experiments indicate that the performance of the mechanism can meet the requirement of precision for grating tiling.     

PATH FOLLOWING GPS-BASED CONTROL OF SMALL-SIZE ROBOTIC UNMANNED BLIMP

Robotic unmanned blimps own an enormous potential for applications in low-speed and low-altitude exploration,surveillance,and monitoring,as well as telecommunication relay platforms. To make lighter-than-air platform a robotic blimp with significant levels of autonomy,the decoupled longitude and latitude dynamic model is developed,and the hardware and software of the flight con-trol system are designed and detailed. Flight control and navigation strategy and algorithms for way-point flight problem are discussed. A result of flight experiment is also presented,which validates that the flight control system is applicable and initial machine intelligence of robotic blimp is achieved.     

QUALITY CONTROL OF SEMICONDUCTOR PACKAGING BASED ON PRINCIPAL COMPONENTS ANALYSIS

5 critical quality characteristics must be controlled in the surface mount and wire-bond process in semiconductor packaging. And these characteristics are correlated with each other. So the principal components analysis(PCA) is used in the analysis of the sample data firstly. And then the process is controlled with hotelling T2 control chart for the first several principal components which contain sufficient information. Furthermore, a software tool is developed for this kind of problems. And with sample data from a surface mounting device(SMD) process, it is demonstrated that the T2 control chart with PCA gets the same conclusion as without PCA, but the problem is transformed from high-dimensional one to a lower dimensional one, i.e., from 5 to 2 in this demonstration.     

PRESSURE FORCE CONTROL FOR FABRICATION OF PLASTIC MICROFLUIDIC CHIPS WITH HOT EMBOSSING METHOD

A pressure force control system for hot embossing of microfluidic chips is designed with a moment motor and a ball bearing lead screw. Based on the numeric PID technique, the algorithm of pulsant integral accelerated PID control is presented and the negative effects of nonlinearity from friction, clearance and saturation are eliminated. In order to improve the quick-response characteristic, independent thread technique is adopted. The method of pressure force control based on pulsant integral accelerated PID control and independent thread technique is applied with satisfactory control performance.     

SPOT WELDING QUALITY FUZZY CONTROL SYSTEM BASED ON MULTISENSOR INFORMATION FUSION

The multisensor information fusion technology is adopted for real time measuring the four parameters which are connected closely with the weld nugget size(welding current,electrode displacement,dynamic resistance,welding time),thus much more original information is obtained.In this way,the difficulty caused by measuring indirectly weld nugget size can be decreased in spot welding quality control,and the stability of spot welding quality can be improved.According to this method,two-dimensional fuzzy controllers are designed with the information fusion result as input and the thyristor control signal as output.The spot welding experimental results indicate that the spot welding quality intelligent control method based on multisensor information fusion technology can compensate the influence caused by variable factors in welding process and ensure the stability of welding quality.     

ONLINE MODEL AND ACTUATOR FAULT TOLERANT CONTROL FOR AUTONOMOUS MOBILE ROBOT

A novel fault-tolerant adaptive control methodology against the actuator faults is proposed. The actuator effectiveness factors (AEFs) are introduced to denote the healthy of actuator, and the unscented Kalman filter (UKF) is employed for online estimation of both the motion states and the AEFs of mobile robot. A square root version of the UKF is introduced to improve efficiency and numerical stability. Using the information from the UKF, the reconfigurable controller is designed automatically based on an enhancement inverse dynamic control (IDC) methodology. The experiment on a 3-DOF omni-directional mobile robot is performed, and the effectiveness of the proposed method is demonstrated.     

ROBUST CONTROL OF GAS TUNGSTEN ARC WELDING SYSTEM

The robust control law for gas tungsten arc welding dynamic process, which is a typical sampled-data system and full of uncertainties, is presented. By using the Lyapunov second method, the robust control and robust optimal control for a class of sampled-data systems whose underlying continuous-time systems are subjected to structured uncertainties are discussed in time-domain. As a result, some sufficient conditions of robust stability and the corresponding robust control laws are derived. All these results are designed by solving a class of linear matrix inequalities (LMIs) and a class of dynamic optimization problem with LMIs constraints respectively. An example adapted under some experimental conditions in the dynamic process of gas tungsten arc welding system in which the controlled variable is the backside width of weld pool and controlling variable pulse duty ratio, is worked out to illustrate the proposed results, it is shown that the sampling period is the crucial design parameter.     

THEORETICAL AND EXPERIMENTAL STUDY ON THE PRESSURE AND VACUUM CONTINUOUS CONTROL SYSTEM BASED ON HYBRID PUMP

A novel pressure and vacuum continuous control system, which adopts a hybrid pump as pressure and vacuum source, is presented. The mathematical model of the system is developed. The theoretical simulation and analysis on the system are implemented in order to study the relationships among the characteristics, parameters and working points of the system. The experimental investigations on the system characteristics are presented with the adoption of a fuzzy-PID controller. The simulation and experimental results indicate that the pressure and vacuum continuous control system based on hybrid pump has good dynamic and static performance, strong robustness and satisfactory adaptability to various system parameters. According to the results, system can successfully gain high accuracy and fast response signal. Also, the mathematical model of system is also testified by the experimental results.     

GA-BASED PID NEURAL NETWORK CONTROL FOR MAGNETIC BEARING SYSTEMS

In order to overcome the system non-linearity and uncertainty inherent in magnetic bearing systems, a GA(genetic algorithm)-based PID neural network controller is designed and trained to emulate the operation of a complete system (magnetic beating, controller, and power amplifiers).The feasibility of using a neural network to control nonlinear magnetic beating systems with unknown dynamics is demonstrated. The key concept of the control scheme is to use GA to evaluate the candidate solutions (chromosomes), increase the generalization ability of PID neural network and avoid suffering from the local minima problem in network learning due to the use of gradient descent learning method. The simulation results show that the proposed architecture provides well robust performance and better reinforcement learning capability in controlling magnetic bearing systems.     

FUZZY GLOBAL SLIDING MODE CONTROL BASED ON GENETIC ALGORITHM AND ITS APPLICATION FOR FLIGHT SIMULATOR SERVO SYSTEM

To alleviate the chattering problem, a new type of fuzzy global sliding mode controller (FGSMC) is presented. In this controller, the switching gain is estimated by fuzzy logic system based on the reachable conditions of sliding mode controller(SMC), and genetic algorithm (GA) is used to optimize scaling factor of the switching gain, thus the switch chattering of SMC can be alleviated. Moreover, global sliding mode is realized by designing an exponential dynamic sliding surface. Simulation and real-time application for flight simulator servo system with Lugre friction are given to indicate that the proposed controller can guarantee high robust performance all the time and can alleviate chattering phenomenon effectively.     

APPLICATION OF FRF ESTIMATOR BASED ON ERRORS.IN-VARIABLES MODEL IN MULTI-INPUT MULTI-OUTPUT VIBRATION CONTROL SYSTEM

The FRF estimator based on the errors-in-variables(EV)model of multi-input multi-output (MIMO)system is presented to reduce the bias error of FRF H1 estimator.The FRF H1 estimator is influenced by the noises in the inputs of the system and generates an under-estimation of the true FRF. The FRF estimator based on the EV model takes into account the errors in both the inputs and outputs of the system and would lead to more accurate FRF estimation.The FRF estimator based on the EV model is applied to the waveform replication on the 6-DOF (degree-of-freedom) hydraulic vibration table.The result shows that it is favorable to improve the control precision of the MIMO vibration control system.     

OPTIMAL TORQUE CONTROL STRATEGY FOR PARALLEL HYBRID ELECTRIC VEHICLE WITH AUTOMATIC MECHANICAL TRANSMISSION

In parallel hybrid electrical vehicle (PHEV) equipped with automatic mechanical transmission (AMT), the driving smoothness and the clutch abrasion are the primary considerations for powertrain control during gearshift and clutch operation. To improve these performance indexes of PHEV, a coordinated control system is proposed through the analyzing of HEV powertrain dynamic characteristics. Using the method of minimum principle, the input torque of transmission is optimized to improve the driving smoothness of vehicle. Using the methods of fuzzy logic and fuzzy-PID, the engaging speed of clutch and the throttle opening of engine are manipulated to ensure the smoothness of clutch engagement and reduce the abrasion of clutch friction plates. The motor provides the difference between the required input torque of transmission and the torque transmitted through clutch plates. Results of simulation and experiments show that the proposed control strategy performs better than the contrastive control system, the smoothness of driving and the abrasion of clutch can be improved simultaneously.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.