Detektering, målföljning och identifiering med robotsystem 90

The objective was to clarify whether and how it is possible to detect, track and identify with an EO/IR (electro optical/infrared) sensor. Moreover, the sight of robotic system 90 was tested in order to clarify the possibilities of using it as a sensor. The sight has a field of view of 3x4° with the TV camera and 4x6° with the IRV camera. Therefore, the project focused on a moving sensor, in order to be able to scan a larger area. By background subtraction it´s possible to detect changes, i.e., movements. The background must move with the sight and therefore requires measurements of the sight direction to be accurate. Detection was made possible by noise reduction of the measured values using a Kalman filter. The maximum scan rate of the sight was 10.8°² /s. The sight can thus not be used as a sensor because the scanning speed is judged to be too low. Kalman filters may also be used to filter the detections and for a short time predict the target path. With a scaling matrix, error in the velocity vector was reduced when the target was not manoeuvring and the target movement could be predicted over time. However, it led to delays when the target manoeuvred, resulting in poor accuracy of the target position. The video color from the sight is in grayscale, which means that the color couldn´t be used to identify aircraft. The aircraft is dark with the TV camera and bright with the IRV camera. What was left then was to identify the type of aircraft by analysing the shape. An existing method for identification by shape analysis is HOG (Histogram of Oriented Gradients). A large amount of training data was required for the support vector machine to handle the differences in shape depending on the sensor viewing angle, the aircraft´s rotation and the relatively small pictures. However, the reliability of the method was still not high enough. Two custom methods were therefore tested in order to try to identify targets by shape analysis. In the first method a 3D model of an airplane was built. The identification would be done by rotating and projecting the model to a two-dimensional image which was compared with the image of the target. Finding the best three-dimensional rotation is a problem which can be solved only by testing all solutions. Therefore, it takes too long to identify with this method. The second method aims to analyse the shape by rotating the two-dimensional image so that the nose is pointing along the x-axis of a two-dimensional coordinate system. Wings were then analysed by analysing the values on the y-coordinates relative to the x-coordinates. Maxima, minima and the gradients were analysed in order to place the wings, estimate their relative size to each other and the shape of the aircraft. Method two may be used to increase the reliability of the identification of the aircraft. An autonomous combat system requires the identification to be very reliable, thus requiring the use of an optical zoom to enlarge the images. More parameters such as position, speed and size should also be analysed when identifying the target

Snabb processreglering med transient börvärde

Syftet med detta arbete var att minimera insvängningstiden av en temperaturreglering. Det görs genom att påbörja regleringen medan börvärdet fortfarande är i den transienta delen av insvängningen. Detta innebär att börvärdet skall filtreras med ett digitalt lågpass filter för att ta bort mätbrus. Filtreringen i sin tur orsakar en fördröjning till den transienta delen av insvängningen. Därmed skall lågpass filtret vara grovt i början av processen för att inte någon märkbar fördröjning skall ske och sedan ändras filtret linjärt sådant att filtreringen blir fin mot slutet. Detta minimerar filtrets fördröjning till insvängningen. Genom att mäta derivatan för bör- och ärvärdet och sedan styra ärvärdets derivata mot börvärdet kan en optimal insvängning åstadkommas. Slutligen skall regulatorn vara adaptiv eftersom tidskonstanten för processen är okänd.The goal of this thesis is lower the settling time of a temperature control process. The process consists of a transient phase and a stable phase. Currently the controller doesn't react until the stable phase is reached. The improved controller will start controlling the process during the transient phase. This is made possible by implementing a digital low pass filter that linearly increases the smoothing of the measured setpoint. A digital low pass filter that applies excessive smoothing during the transient phase would cause a delay that would ultimately increase the settling time. As an additional control parameter the derivative of the setpoint is used to control the temperature during the transient phase. During the transient phase the controller relies on the derivative to controll the process while the error is used more during the stable phase. The controller can only apply heating not cooling.Tämän työn tavoitteena on lyhentää lämpöohjausprosessin asettumisaikaa. Prosessi koostuu kahdesta eri vaiheesta, ohimenevästä ja stabiilista. Lyhenetty asettumisaika saavutetaan aloittamalla säätäminen transientin vaiheen aikana. Alkuperäinen ohjain odottaa asetusarvon stabilisoitumista ennen kuin säätäminen aloitetaan. Uudella ohjaimella pyritään aloittamaan säätäminen transientin vaiheen aikana. Tämän mahdollistaa digitaalinen matalapäästösuodatin, jonka vahvuus muuttuu linearisesti prosessin aikana. Liiallinen suodattaminen prosessin alussa johtaa viiveeseen, joka pidentää asettumisaikaa. Transientin aikana käytetään erosuureen lisäksi asetusarvon sekä prosessin todellisen arvon derivaattaa. Näin pystytään ohjaamaan todellinen arvo seuraamaan asetusarvon käyttäytmistä transientin vaiheen aikana. Prosessiin voidaan ainoastaan vaikuttaa säätämällä lämpöä

Kamratgranskning av laborationsförberedelser i reglerteknik

Laborationer är ett frekvent återkommande inslag i kurserna vid Institutionen för Regerteknik. Laborationerna tar mycket resurser i anspråk, och det är därför viktigt att skapa förutsättningar för att studenterna skall få ut så mycket som möjligt av dem. Studenterna förväntas inför varje laboration läsa på relevanta delar av kursmaterialet, samt i vissa fall även lösa några förberedelseuppgifter. Det skriftliga förhör som traditionellt tillämpats för att testa studenternas förkunskaper inför laborationen har medfört att studenterna ofta upplevt stress inför laborationerna. För att skapa en mer positiv undervisningssituation har kamratgranskning av förkunskaper i grupp provats. Reaktionerna från studenterna och har varit mycket positiva. Våra erfarenheter är också positiva, även om vissa mindre signifikanta negativa bieffekter observerats

Flexibelt linjärservo med inverterad pendel

This master thesis is the first step in developing a new laboratory process for the automatic control basic course. The new process should illustrate the benefits of state-space control compared to PID control. A process with several outputs to control is then desired as a single PID controller does not support such a system. The suggested process consists of two carts mounted on a linear rail and connected by a spring, one driven by a DC motor and one trailing along holding a pendulum. The overall goal of the laboratory will be to balance the pendulum upright. This could be done with PID control but with the slight drawback of not being able to control the cart positions. Thus it would not be suitable for a real process of this kind since the rail is not infinitely long. The state-space controller and observer needed to position the carts arbitrarily while balancing the pendulum are implemented in Matlab and Simulink environment, whereas the I/O interface is handled by an Atmel AVR microcontroller (ATMEGA8). The rail and cart chassis were bought from a local company and modified into modules, enabling the process to change into several shapes. The positioning hardware and driver circuits were developed at the department. The main effort has been to make all these parts work together. Programming the AVR in order to drive the machine, communicate with Simulink and handle position encoding has demanded some hard work. The report deals with issues considering simple D/A Pulse Width Modulation and positioning with state machine with interpolation for extended resolution. The process of modeling this system is also treated together with the basic control theory needed for accurate performance. This master thesis has resulted in a price worthy, fully functional and controllable LFJCIP-process for educational purpose