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278 results about "Control chart" patented technology

Control charts, also known as Shewhart charts (after Walter A. Shewhart) or process-behavior charts, are a statistical process control tool used to determine if a manufacturing or business process is in a state of control. It is more appropriate to say that the control charts are the graphical device for Statistical Process Monitoring (SPM). Traditional control charts are mostly designed to monitor process parameters when underlying form of the process distributions are known. However, more advanced techniques are available in the 21st century where incoming data streaming can-be monitored even without any knowledge of the underlying process distributions. Distribution-free control charts are becoming increasingly popular.

Cloud application fault diagnosis system based on statistical monitoring

The invention provides a cloud application fault diagnosis system based on statistical monitoring. The cloud application fault diagnosis system based on statistical monitoring comprises a monitoring agent, a running status tracker and a fault detection locator, wherein the monitoring agent is used for collecting monitoring information when a cloud application runs; the running status tracker is used for abstracting the running status of the system to be local outlier factors and correlation coefficients; the fault detection locator is used for analyzing the running status of the system according to monitoring data provided by the running status tracker so as to detect a fault and locate reasons of the fault. According to the method, the running status of the system is described from utilization and performance of system resources according to the monitoring data through the local outlier factor and kernel canonical correlation analysis method, the system fault is detected according to a control chart, and abnormal measurements are located through a feature selection method. The method has the advantages that related knowledge of the application such as a software system structure and parameter estimation is not needed, and the method is simple, easy to implement and wide in application range; various faults of the cloud application can be automatically detected without manual intervention, and the abnormal degrees of the measurements can be quantized.
Owner:INST OF SOFTWARE - CHINESE ACAD OF SCI

On-line monitoring method for cutter abrasion damage based on main shaft driving current and working step.

The invention discloses an on-line monitoring method for cutter abrasion damage based on main shaft driving current and working step. The method is made by the following steps that realizing communication with a numerical control system to obtain machining working step information, meanwhile, the driving current and the load of the main shaft are monitored, and on the basis of a normal cutter andabrasion damage cutter cutting torque difference analysis and statistical quality control principle. Control graph for drawing average current / load required by each working step processing, a control graph control line is reasonably formulated, the abrasion state of each working step is judged, and a tool changing or cutter edge grinding rule is formulated. According to the variation of instantaneous main shaft current or instantaneous load with the deviation from the instantaneous current / load in normal machining in each working step of machining, the cutter breakage is determined, the alarm signal is sent to inform the numerical control system to emergency shutdown so as to avoid the serious consequences of damaging the workpiece and the machine tool. According to the method, on onehand, the part rejection rate and the machine tool fault rate can be reduced, on the other hand, the service life of the cutter can be prolonged to the maximum extent, and the use cost of a plant cutter is reduced.
Owner:BEIJING UNIV OF TECH +1

Method for carrying out early warning on damage to steel box girder of long span bridge in operation state

The invention relates to a method for carrying out early warning on the damage to a steel box girder of a long span bridge in an operation state. The method comprises the following steps of: a step 1 of arranging steel box girder sensors, i.e. arranging a vertical acceleration transducer, a temperature sensors and an anemoscope at the midspan positions of the steel box girder for respectively monitoring the vertical acceleration of the steel box girder, the temperature of the steel box girder and the wind speed of a region where the steel box girder is positioned, which are caused by a vehicle load; a step 2 of processing monitoring data; a step 3 of establishing a mathematical correlation model of the vibrating frequency of the steel box girder and operation factors in a good state; a step 4 of determining the significance level of a control chart; and a step 5 of carrying out early warning on the damage to the steel box girder. According to the invention, various factors influencing the variation of the vibrating frequency of the steel box girder in the operation state are comprehensively considered, the real-time performance and accuracy of carrying out early warning on the damage to the steel box girder are effectively improved, and the method is necessarily and widely applied and popularized.
Owner:SOUTHEAST UNIV

Energy-saving stability motion control method for networked car queue

The invention discloses an energy-saving stability motion control method for a networked car queue, and belongs to the technical field of a car driving assistance system. The method includes the stepsof first establishing a single vehicle dynamics model in the networked car queue and calculating the acceleration of each vehicle in a pulse phase and a glide phase; by establishing a car following subsystem model with the relative speed and the relative inter-vehicle distance error of a car following subsystem composed of two adjacent vehicles as state variables, determining four driving modes of the car following subsystem to obtain a host vehicle state trajectory on a [delta]v-[delta]R plane; for the pulse or glide cases of a front vehicle, obtaining host vehicle [delta]v-[delta]R state plane partition maps respectively, and determining the host vehicle acceleration of each range; and finally, synthesizing the host vehicle state plane partition maps obtained respectively for the pulseand glide cases of the front vehicle, and obtaining a switching control chart and a control law of the host vehicle to achieve energy-saving motion control of the vehicles in the networked car queue.The method in the invention has low requirements on the precision of the position control of the vehicles and has the effect of high fuel efficiency.
Owner:TSINGHUA UNIV

Drilling machine system based on sliding guide drilling closed loop control and drilling method

The invention relates to a drilling machine system based on sliding guide drilling closed loop control and a drilling method. The system comprises a dynamic measuring unit sub system, a ground monitoring sub system, an execution sub system and a guide drilling system, wherein the dynamic measuring unit sub system measures the parameters such as the well deviation, the orientation and the tool surface of an underground power drill tool in real time, and sends the parameters to the ground monitoring sub system; the ground monitoring sub system achieves the goal of re-determining the trace of a borehole to be drilled according to the designed borehole track and the target point when the condition that the borehole track deviates the designed borehole track is found through comparison; the ground monitoring sub system determines the top drive/turntable rotating angle and the drilling pressure regulation strategy through being combined with a top drive/turntable-drilling pressure combined control chart obtained according to the many-body dynamics simulation design analysis, and then dynamically regulates the drilling pressure and the drift of the tool surface of the underground power drilling tool through regulating the rotating angle of a top drive/turntable and the speed of a traveling block by the execution sub system, so that the stability of the underground tool surface and the drilling pressure is maintained; the closed loop automatic control of the sliding guide drilling borehole track is realized; the operation efficiency and the control precision of the directional well borehole track are effectively improved; and the borehole quality is improved.
Owner:CHINA NAT OFFSHORE OIL CORP +1

Method for making omega event interval control chart for high quality process statistics control

The invention discloses a method for making an omega event interval control chart for high quality process statistics control. In the method, a production process is supposed to be complied with normal distribution, and the production process and the normal distribution are independent; as a high quality process is sensitive to a false alarm rate, a time interval of an omega event is monitored in order to reduce the false alarm rate; and if the time interval is abnormal, the process is abnormal and is out of control. The method specifically comprises the following steps of: 1, acquiring historical data; 2, performing statistical description on the historical data; 3, designing parameters of the omega event interval control chart; 4, monitoring the process by using the omega event interval control chart; 5, judging whether the process is really out of control; and 6, analyzing a reason why the process is out of control, and adjusting and repairing the process to make the process reenter a controlled state. By the method, the problems of high false alarm rate of the conventional control chart in high quality process monitoring application and the like can be solved; furthermore, the method has high reference value for process alarm diagnosis and has a wide application prospect in the technical field of statistical process control technologies.
Owner:BEIHANG UNIV

Statistical process control method of mean-standard deviation control charts of samples of different sizes

The invention discloses a statistical process control method of mean-standard deviation control charts of samples of different sizes, and mainly solves the problem that existing control charts cannot implement statistical process control when samples are different in size. The implementation steps include: 1. obtaining product samples; 2. calculating to obtain a mean value and standard deviation of each set of samples; 3. obtaining a matrix mean value and standard deviation; 4. calculating respective corresponding characteristic values of two control charts in the mean-standard deviation control charts, and obtaining respective corresponding control lines of the two control charts in the mean-standard deviation control charts; 5. according to a drawing method of a Shewhart control chart, drawing corresponding control charts with the characteristic values and control lines; and 6. using a process abnormality judgment criterion to judge the control charts in the Step 5, so as to obtain a result of whether a production process is in a controlled state. The statistical process control method provided by the invention has a wide range of application, calculation accuracy of the mean value and standard deviation of the matrix is high, and the method can be used for statistical process control of samples of the same size or different sizes.
Owner:XIDIAN UNIV

Civil engineering structure damage pre-warning method in consideration of temperature influence

The invention relates to the field of civil engineering structure damage identification, in particular to a civil engineering structure damage pre-warning method in consideration of a temperature influence. An AR model in time series analysis and principal component analysis in multivariate statistical analysis are utilized, and a standard deviation control chart is combined for structure pre-warning research. Firstly, accelerated speed response data before and after structure damage are fit by the AR model, and a model coefficient is extracted; secondarily, the influence of temperature on the AR model coefficient is removed through principal component analysis; and finally, damage pre-warning is performed by using a standard deviation control chart. The pre-warning method is rigorous in theory, novel, reasonable in scheme and high in operability. The civil engineering structure damage pre-warning method has the advantages that accelerated speed response is directly used, a finite element model and modal parameters are not required, and the method belongs to a data driving method and is suitable for performing structure health monitoring in real time; and simultaneously, according to the method, under the condition of temperature change, the damage pre-warning is successfully performed through the anti-noise capacity.
Owner:QINGDAO TECHNOLOGICAL UNIVERSITY

Quality homogenized evaluation method for multi-spot produced cigarette products and difference index screening method

The invention discloses a quality homogenized evaluation method for multi-spot produced cigarette products and a difference index screening method, which belong to the field of cigarette quality homogenized evaluation. The method is improved on the basis of the prior art. In the method, a lower limit which can be accepted by a main plant, namely a 6 or 3 sigma lower limit is calculated by using n index detecting results according to a Shewhart control chart theory; on the premise that the products are qualified in routine examination, the homogenized evaluation is performed between plants and the main plant or among the plants by using the Euclidean similarity coefficient matrixes of the plants; and by comparing and analyzing the inter-index variation coefficients of one couple or a plurality of couples of plants with the highest Euclidean similarity coefficients with the inter-index variation coefficients of one couple or a plurality of couples of plants with the lowest Euclidean similarity coefficients, the indexes are screened according to the condition that the absolute value of the difference of the variation coefficients is more than or less than 1 percent, and the screened indexes are the indexes which highly influence the quality difference of the products of the different plants. The method has the advantages of high operability and comprehensive and accurate detecting result, and is novel.
Owner:YUNNAN RES INST OF TOBACCO SCI

Method for controlling operation of screw pump well by utilizing dynamic control chart of screw pump well

The invention relates to a method for controlling the operation of a screw pump well by utilizing the dynamic control chart of the screw pump well, which solves the problem that the prior art lacks a method for reasonably controlling the pump conditions of the screw pump well. The method is characterized in that the dynamic control chart program of the screw pump well is compiled according to theformula on the basis of the corresponding relationship between the volume efficiency and flow pressure of the screw pump well and the known data; the control chart is divided into five regions, namely a region to be verified, a reasonable working region, a parameter small region, a parameter large region and a breakage loss region; the positioning of the screw pump well in the dynamic control chart can be obtained after the volume efficiency of the screw pump well in the operation course and the flow pressure value at the bottom of the well are input into a computer; and the specific measuresof regulating the parameters, inspecting a pump, exchanging the pump, pressing crack, acidizing, regulating the injection amount of an injection well and the like are formulated according to the region where the screw pump well is. The method can guide technical personnel to analyze the pump conditions and can specifically formulate the specific measures according to the distribution of well points in the control chart, thereby improving the production conditions of the screw pump well and enhancing the work efficiency of the screw pump well.
Owner:DAQING OILFIELD CO LTD +1

Control method and equipment for oil injection quantity in case of sudden increase of torque of engine

The invention provides a control method and equipment for oil injection quantity in case of sudden increase of torque of an engine. When the torque of the engine is suddenly increased, the torque change rate is judged to be greater than a change rate calibration value; and when a torque demand value is judged to be greater than a torque threshold value, a new oil quantity limit value control curve is started to control the oil injection quantity. Therefore, when the torque of the engine is suddenly increased, larger oil injection quantity is provided for the engine, flame-out of the engine is avoided, and normal work of the engine is guaranteed. The original oil quantity limit value control chart is three-dimensional, the rotation speed and the torque are input, and the oil injection quantity is output. The rotation speed is in one-to-one correspondence relation with the maximum oil injection quantity. The oil injection quantity in case of sudden increase of the torque is limited by the maximum oil injection quantity corresponding to the rotation speed. In the new oil quantity limit value control curve provided by the invention, the maximum oil injection quantity limit value corresponding to the rotation speed is greater than the maximum oil injection quantity limit value corresponding to the same rotation speed in the original oil quantity limit value control chart. When the torque is suddenly increased, the requirement of the engine on the oil injection quantity is met, and no flame-out of the engine is guaranteed.
Owner:WEICHAI POWER CO LTD

Industrial enterprise large user water consumption abnormity monitoring and early warning method

The invention discloses an industrial enterprise large user water consumption abnormity monitoring and early warning method. The method comprises the steps of firstly, establishing an industrial enterprise water consumption monitoring database; secondly, calculating dynamic 24-hour water consumption in a historical stable period, performing normal distribution verification on a 24-hour water consumption sequence by adopting KS (Karst Square) examination, and calculating upper and lower limit parameters of the box line diagram when the normal distribution is skewed distribution; and when the distribution is normal distribution, calculating the parameters of the SPC control chart. Finally, SCADA actual measurement data are obtained, 24-hour water consumption is calculated in a rolling mode at each sampling moment and compared with an upper limit threshold value and a lower limit threshold value, and over-limit judgment and early warning are conducted. The upper and lower bound thresholdsof the dynamic 24-hour water consumption of the industrial enterprise are determined through data mining; according to the method and the system, the normal or skewed distribution condition is considered, the practical problems of uncertainty of water consumption of large users of industrial enterprises and difficulty in water company supervision are well solved, the accuracy of automatic monitoring and early warning of water consumption abnormity of the industrial enterprises is improved, and a three-level DMA abnormity monitoring means of water companies is perfected.
Owner:HANGZHOU DIANZI UNIV
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