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11431 Uppsatser om Inventory control system - Sida 1 av 763

Utveckling av modellbaserad reglering i kommersiella styrsystem

In industrial control systems PID-control remains the prevalent strategy, also for processes that would benefit from model based control. The purpose of this thesis is to evaluate whether model based control can be readily implemented in an industrial control system. To this end a simulated surge tank with a simulated industrial control system is studied. For evaluation two scenarios with specified objectives are selected.Following a review of LQR and versions of MPC, Predictive Functional Control (PFC) is considered the most suitable for implementation. PFC is a form of MPC developed with industrial applications in mind and therefore has several advantages for implementation in an industrial control system.

En studie om artikelhantering i material- och produktionsstyrningssystem på System Andersson AB

This thesis aims to develop a control system for measuring electromagnetic compability (EMC). This has meant that a controller designed around an ATmega8 microcontroller has been manufactured and programmed. It has also meant the development of a comprehensive control software in the program MATLAB. The control system has been tested with satisfactory results and can now, monitor and control measurements of the EMC-type..

Äga eller leasa lagret i ett mindre handelsföretag?

Small companies have fewer resources which often result in an tendency to disregard  administrative tasks. A factor that influences the company?s revenues is the control of its inventories. The purpose of the current study was to analyze which of the two options, leasing or owning your inventory, that could be justified from an economical perspective. Furthermore, the purpose was to describe the optimal inventory level for each option. To meet these objectives representatives for the company was interviewed and a thorough investigation process was undertaken, during which methodological problems were solved.  It was found that leasing the inventory was the most expensive option for the company. Analysis demonstrated that optimal turnover inventory according to EOQ (Economic Order Quantity) would amount to 65,0 thousand Swedish Krona if the company leases their inventory in comparison to 56,0 thousand Swedish Krona if the company owned their inventory.

Utveckling av styrsystem för EMC-kammare

This thesis aims to develop a control system for measuring electromagnetic compability (EMC). This has meant that a controller designed around an ATmega8 microcontroller has been manufactured and programmed. It has also meant the development of a comprehensive control software in the program MATLAB. The control system has been tested with satisfactory results and can now, monitor and control measurements of the EMC-type..

Effektivare ytterbelysning inom Karlstads Bostads AB :  

This report is an inventory of the street lighting in half of the residential estates owned by Karlstad Bostads AB, a public housing company. The inventory was made to reduce the environmental impact of the street lighting. From the inventory an estimation of the total installed power and the energy consumption was made. The total estimated power of the street lighting was 125 kW and the energy consumption was 500 000 kWh/year with an estimated running time of 4 000 h/year. The dominating source of light was 125 W discharge mercury lamps.

When companies grow up - A case study of a family-owned company?s management control system

Problem: What are the characteristics of Polykemi?s management control system and how is it affected by growth? Purpose: To describe and analyse the management control system of a medium-sized family-owned company from the perspective of Simons? Levers of control. Research design: An abductive, interview-based case study of Polykemi AB. Conclusion: Polykemi?s management control system is primarily a traditional one which is rather strong in terms of Levers of control.

Rundstyrning i lokalnät : En förstudie i tekniska och ekonomiska konsekvenser för Värnamo Elnät AB

Värnamo Elnät owns and operates a ripple control system which is used to control loadsespecially when the grid is heavily loaded and for control of street lighting. This report aims atclarifying technical and economic aspects of the ripple control system?s future. The system wasinstalled from 1975 and onwards and its use was greater in those days when the controllableloads where greater then today, the current controllable load level is about 3 MW. The reporthighlights three different aspects of the ripple control system?s future ? retain the currentsystem, reinvest in a newer system or discontinue the system.In the report the author also discusses relevant connections to Smart Grids and future meteringsystems and tariffs.

Sambandet mellan saldodifferenser och effektivitet : En fallstudie på utomhuslager inom Sandvik Materials Technology

To meet the needs and demands of the costumer, accurate information about how much is available in stock is necessary. When the information in the system does not match the physical inventory, inventory inaccuracy occurs. Inventory inaccuracy is common among companies and may contribute to increased labor cost, excess inventory, production disruptions, waste of time, late deliveries, poor service and lost customers.The purpose of this study is to identify contributing factors to inventory inaccuracy for business with outdoor storage. The study also aims to investigate how efficiency factors can reduce the inventory inaccuracy for business with outdoor storage.A case study was conducted to answer the purpose. A company in the steel industry was chosen to examine inventory inaccuracy on business with outdoor storage.

Testsystem för utredning av integrerad styrning för RC-helikopter

AbstractThis report is about the creation of a test system for development of a control system for a off the shelf RC-helicopter, which can be bought for about two thousand SEK. The test system consists of both electronics for controlling the helicopter and mechanical constrainer. The constrainer is used for mounting the helicopter so that it won´t crash.A circuit board including processor and sensors was manufactured. This was used for doing test of the different control algorithms. In this way were we able to analyze the quality of the sensors chosen, and what other sensors that could contribute to the control of the system.Basic helicopter control have been studied and presented in the report.

Verksamhetsstyrningens inverkan på målprioritering - En kvalitativ fallstudie av två vårdcentraler i Stockholms läns landsting.

This study aims to examine the effect management control systems have on which goals health centers prioritize. The management control systems of one privately owned and one publicly owned health center have been studied through a qualitative case study. Robert Simons (1995) framework with four levers of control (diagnostic control systems, interactive control systems, belief systems and boundary systems) has been used to structure the study. For both health centers we found a conflict of interest mainly between the diagnostic control system and the beliefs system, where the diagnostic control system is biased towards quantitative goals and the beliefs system is mainly biased towards qualitative goals. However, despite the unbalanced levers of control the studied health centers have been able to reach a well functioning compromise between quantitative and qualitative goals..

Modellbaserad drivlinereglering

A cars powertrain consists of everything that is needed for its propulsion. The components in the driveline that transfer the power from the engine to the driven wheels are not absolutely stiff, hence they will wind up due to the torque and act as torsion springs. If you suddenly demand a bigger torque by stepping on the accelerator pedal, a so called tip in manoeuvre, and that torque is acquired from the engine as quickly as possible, the driveline will not be able to transfer that fast torque change due to its weakness and as a result it will start to oscillate. These oscillations will be transferred to the driven wheels and make the car to accelerate jerkily which will be experienced as uncomfortable by the passengers. Furthermore, there is a backlash in the driveline that will make the weakness in the driveline even more excited than it should have been if the backlash did not existed.To avoid too big problems with these oscillations there is a control system that controls the demanded torque.

Samverkande, motverkande eller kompletterande? : En uppsats om relationer mellan styrsystem

Title: Co-operative, prevent or complement? - An essay on the relationships between control systems. Authors: Kim Eriksson and Victoria KarlssonPurpose: The essay aims to describe the relations between control systems and how they related to each other, based on an operationalization of the control systems. Research question: What are the control systems relations to each other? With regards whether control systems co-operative, prevents and/or complement each other.Theoretical framework: The essays theoretical framework is based on Malmi and Browns (2008) description of five different control systems and control mechanisms associated with each control system.   Research methodology: The method was based on three different data collection methods. These methods were observations, documentation, and semi-structured interviews.Conclusions: It is concluded that the control systems has comprehensive relations. Control systems have more, than one, relation to each other..

Acne Jeans och Öresund: Hur förändras verksamhetsstyrningen i ett kreativt modeföretag när det inleder samarbete med ett riskkapitalbolag?

We have performed a case study on Acne Jeans, a creative Swedish fashion company, which initiated a cooperation with the Swedish venture capital firm Öresund. The aim of our paper was to examine what motivates a venture capital firm to transform the management control system of a creative company, into a more formal system of control. Main results: Öresund did not have an excessive impact on the management control system of Acne Jeans, due to three main reasons. First of all, Acne Jeans had a satisfactory management control system prior to the cooperation. Furthermore, the relationship between the two parties was characterized by mutual trust.

Robotstyrning med metoden Sliding Mode Control

The task in this thesis is the steering of one of Saab Bofors Dynamics robots using Sliding Mode Control, a method they never used before. The robot constitutes a system which in addition to perturbations and uncertainties due to modeling imprecision, hold the difficulty of being highly time variant. In order to be able to keep required performance with uncertainties and modeling imprecision present, the use of robust control methods like Sliding Mode Control is necessary. SMC is based on the states of the system being forced to stay on or in the direct vicinity of a hyper plane in the state space which is chosen in a way that gives the system dynamics desired properties. Other advantages with sliding mode are reduced order dynamics on the switching surface and total insensitivity to some uncertainties and perturbations.

Automatisering av spraytorkningsprocess

ABB Surge Arrestors in Ludvika have for a long time had a problem to keep the moisture at a steady state in the production of their ZnO-powder, that is used to produce varistors.Some black-box models of the spray drying process have been designed and evaluated to find a solution for the problem. After evaluating the collected data it has been found that variations in the supply voltage causes control difficulties for the operator. A cascade control system was designed, consisting of three PI control loops designed with lambda tuning. The disturbance in the supply voltagewas used as a feed forward in the control system.At the end of the project the control system was installed, and tests were made to verify the functionality of the regulator. It was shown that most of the variations in the moisture of the powder could be eliminated using small resources, through purchase of a process controller and four power meters.

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