An Expert System for the Scheduling of a Flexible Assembly Line for Multi Item Products

An expert system, in which preconditions and rules are expressed in logical formulas, is developed to support the scheduling of an automated job shop type multi-item assembly line. This system has the foIIowing characteristics to apply any case of schedulings: (1)Forward scheduling orbackward scheduling can be made. (2)The criterion on the input order of products, the dispatching process at each assembly station, and the selection of products from a buffer can be selected from several priority criteria. (3)Layout, number and velocity of vehicles, and the capacity of each buffer can be changed

An Expert System for Determining Precedence Relation in Assembly

Precedence relation in assembly has been determined by experience only. Now, an expert system is developed for determining such precedence relation. The conjugate states of the units of a product are shown in face frames and unit frames following the frame model. Seven rules are formulated. They consider geometrical interference of units, and make the precedence relation enable operation time to be shorter, and the number of JIG and substandards to be smaller. These rules are programized by computer language(PROLOG)

Price Determination Method Based on Price Elasticity

In this paper, we propose the price determination method using the parameter of the price elasticity that shows the relation between price and demand. Firstly, the state of the price elasticity is examined under the condition that the relation between price and demand are assumed by the inverse proportional function, the linear function and the quadratic function. Secondly, the profit is estimated for each product by break even point analysis. And the price is determined under the condition that the relation between the demand and price is shown by one of three　demand-pridce functions above mentioned

A Method for Designing the Supplying Method of Parts to an Assembly Line

We propose a method to design the supplying method of parts to an assembly line. Three types of supplying model (Serial, Parallel, and Mixed) are proposed based on the relation between the area of part and that of the transportation equipment. The part is supplied by the pallet on which the all parts of one product are arranged or by the lot of one part. AGV or conveyor are used to transport the pallet. The supplying model is evaluated from the total transportation cost calculated from the price of the transportation equipment and of land

Recognition Index of Part and Unit by Discrimination Characteristics

In this paper, we propose a recognition index to evaluate the complexity of discrimination among parts and units. The parts and units are classified into some groups (the number of groups is shown as n) by one characteristic, such as color, shape, size and so on. The recognition index of each is denoted as log(2) (n+1) by the information quantity formula. The recognition diagram shows the classfication of parts and units into only one part and unit by the structure of a characteristic. Further we propose the line balancing method for assembly line based on the working time and recognition index

On a Relation between the Flicker Value and the Vibration

Insuring fast and precise human operation is one of the engineering requirements in the developing civilization. Some man-machine system, when any operator is exposed himself to some kind of vibration, he may not perform his operation in good conditions. Then one of the interferring factors, there is a fatigue caused by vibration. In this study, subjects sit on the chair which was set on the vibration table, and were shaken vertically for some given times, then were measured whether the fatigue occured or not by flicker friction tester. Flicker patterns were analyzed according to each vibration-condition, then the authors knew that the fatigue was occured by vibration

Intelligent Monitoring System Using Multiviewpoints for Teleperation

In this paper, we propose the method to determine the position of the 2 cameras for the multiviewpoints as the robot is the work place. The optical axit's direction of the 1st camera is determined in the base ot work contents in teleoperation. The multiviewpoints system uses the 2 camera units that aren't installed side by side, so that the direction of the 2nd camera is decided in the base of the angle between the optical axes' direction of 2 cameras. Next, the distance from the camera to the work place is determined according to the distance resolution of image on the monitor, and the camera type of which the point-blank range is not this distance is selected. And the efficacy ot this system is examined with an experiment

An Expert System for Reducing the Variety of Parts in Multi-item Production

A method for reducing the variety of parts is proposed. The variety of parts in a product and the variety of parts among products are evaluated in consideration of some factors that influence the production cost. Rules are formulated for selecting parts which should be eliminated or whose designs should be changed to reduce these varieties. An expert system is developed based on this method for reducing the variety of parts

Evaluation of the Appropriate Root Pressure for Maintaining Heartbeat during an Aortic Cross-clamp for Primary Repair of the Aortic Arch in Premature Infants with Associated Cardiac Anomalies

We developed a new cardiopulmonary bypass (CPB) method to minimize myocardial damage during aortic arch reconstruction. In this method, coronary flow and heartbeat were stabilized by maintaining the aortic root pressure with an adjusted preload of the ventricle during aortic cross-clamping. This study was performed to determine the appropriate root pressure to maintain the heartbeat without causing deterioration of ventricular function. Study 1. Under partial CPB, the ascending aorta was cross-clamped in 6 pigs (group 1). Experimental data at various systolic aortic root pressures was analysed to determine the appropriate root pressure. Study 2. In group 2 (control, n＝6), the aorta was not clamped, while in group 3 (n＝6), the aorta was cross-clamped for 60 min and the systolic aortic root pressure was maintained at the pressure determined in study 1. Study 1. The diastolic coronary flow was stabilized at values comparable to that before initiation of CPB (6.6±1.4ml/beat) when the systolic aortic root pressure was above 80mmHg. Intracardiac pressure and the myocardial oxygen consumption (MvO2) seemed to be acceptable when the systolic aortic root pressure was below 100mmHg. Therefore, 90mmHg was selected for study 2. Study 2. Perioperative cardiac function did not differ between the groups. We concluded that 90mmHg was the systolic aortic root pressure appropriate for this method

A Method for Design Production System with Multi Energy Resources

This research proposes a strategy for reducing both electricity charge and environmental load by considering multi energy sources. The reduction of the contract electric demand is considered, and its differential cost is used for purchasing substitute power sources. Some variables, such as the amount of reduced contract demand, and amount of electricity are generated by each substitute power source. By using those variables, we formulate a simulation model that enables to minimize the energy cost and environmental cost