This diploma thesis deals with design of machinware of mobile robot. The purpose of this work is to design complete technical product documentation for manufacturing of a prototype. In first theoretical part of this thesis there is an analysis of contemporary situation of mobile robots. In second practical section, there is a design of all needed mechanical parts for tracked vehicle, all needed calculations are included. Diploma thesis contains hazard analysis, complete technical product documentation with 3D model included and final price statement.

The aim of this thesis is to write a multisensor navigation algorithm and to design a test setup. After doing these, test the algorithm by using the test setup. In navigation, dead reckoning is a procedure to calculate the position from initial position with some measured inputs. These measurements do not include absolute position data. Using only an inertial measurement unit is an example for dead reckoning navigation. Calculating position and velocity with the inertial measurement unit is highly erroneous because, this calculation requires integration of acceleration data. Integration means accumulation of errors as time goes. For example, a constant acceleration error of 0.1 m/s^2 on 1 m/s^2 of acceleration will lead to 10% of position error in only 5 seconds. In addition to this, wrong calculation of attitude is going to blow the accumulated position errors. However, solving the navigation equations while knowing the initial position and the IMU readings is possible, the IMU is not used solely in practice. In literature, there are studies about this topic and in these studies / some other sensors aid the navigation calculations. The aiding or fusion of sensors is accomplished via Kalman filter. In this thesis, a navigation algorithm and a sensor fusion algorithm were written. The sensor fusion algorithm is based on estimation of IMU errors by use of a Kalman filter. The design of Kalman filter is possible after deriving the mathematical model of error propagation of mechanization equations. For the sensor fusion, an IMU, two incremental encoders and a digital compass were utilized. The digital compass outputs the orientation data directly (without integration). In order to find the position, encoder data is calculated in dead reckoning sense. The sensor triplet aids the IMU which calculates position data by integrations. In order to mount these four sensors, an unmanned tracked vehicle prototype was manufactured. For data acquisition, an xPC&ndash / Target system was set. After planning the test procedure, the tests were performed. In the tests, different paths for different sensor fusion algorithms were experimented. The results were recorded in a computer and a number of figures were plotted in order to analyze the results. The results illustrate the benefit of sensor fusion and how much feedback sensor fusion is better than feed forward sensor fusion.

Scandinavian Terrain Vehicles AB (STV) konstruerar och bygger bandvagnar för civilt bruk. I utbudet ingår även vad STV kallar Mid Life Improvement (MLI) vilket syftar i att renovera Hägglunds BV206. En del av MLI-programmet är byte av motor och växellåda där de gamla komponenterna från sent 80-tal till tidigt 90-tal byts ut mot ny motor och växellåda. Den nya kombinationen av motor och växellåda möter militär standard och blir därför en onödigt kostsam del då många av STV:s kunder skulle vara nöjda även med ett enklare alternativ. För att minska kostnaden för MLI-programmet och därmed potentiellt utöka kundkretsen undersöktes möjligheterna till att hitta nya leverantörer av motor och växellåda. Som alternativ undersöktes möjligheterna till drift genom diesel- eller Ottomotor samt transmission av typerna automatisk växellåda, hydrostatisk och elektrisk transmission. Sökning av komponenter utgick från att undersöka vilka komponenttillverkare som används av liknande applikationer. Genom en kriterieviktsmetod blev det rekommenderade lösningsalternativet motorn Cummins ISF 2.8 120 kW och växellådan Allison 1000SP. Kombinationen levererar som mest 1384 Nm och vid 5200 rpm 185 Nm till fördelningsväxeln. Resultatet styrks av att motorn enligt tillverkaren är lämpad för fordon såsom mindre lastbilar och terrängfordon samt att växellådor av samma tillverkare används till bland annat BAE Systems Hägglunds bandvagn BvS10. / Scandinavian Terrain Vehicles AB (STV) is a company that designs and builds tracked vehicles for civilian usage. One of their services is what they call Mid Life Improvement (MLI) which serves to recondition Hägglunds BV206’s. A significant part of the MLI-program is the exchange of engine and transmission where components from the late 80’s to early 90’s are replaced with new parts. The new parts consist of a combination of engine and gearbox that meets military standards and is therefore an expensive part especially since many of STV’s customers would settle with a more elementary alternative. To reduce costs within the MLI-program and potentially expand clientele STV sought to find new suppliers for engine and gearbox. Considered alternatives for replacement were Otto- and Diesel engines in coupled with a transmission in the form of either an automatic gearbox, a hydrostatic or an electric transmission. By examining which suppliers were being used by similar applications and selection through a weighted criteria method, the engine Cummins ISF 2.8 120 kW and transmission Allison 1000SP were found to be the best suited alternative. The combination delivers to the distribution gearbox a maximum torque of 1384 Nm and 185 Nm at 5200 rpm. The result is attested by the fact that the engine is according to the manufacturer suitable for applications like trucks and utility vehicles together with that the same brand of transmission is used by BAE Systems Hägglunds in their BvS10.

Tracked vehicles are designed to operate in various terrains, ranging from soft mud to hard tarmac. This wide range of terrains presents significant challenges for the suspension system, as its components must be suitable for all types of terrain. The selection of these components is crucial for minimizing acceleration levels within the vehicle, ensuring that personnel can comfortably endure extended durations inside. BAE Systems Hägglunds AB develops and produces an armored tracked vehicle called the CV90. Within the CV90’s suspension system, a key component known as the torsion bar, a rotational spring, plays a primary role in reducing the vehicle’s motion. The CV90 vehicle has seven wheels on each side, with each wheel having its dedicated torsion bar. To measure the whole-body vibration experienced within the vehicle, a measurement called the Vibrational Dose Value (VDV) is utilized. The main objective of this thesis is to develop a data-driven model to optimize the suspension system by identifying the combination of torsion bars that generates the smallest VDV. The data used for optimization is based on simulations of the CV90 vehicle in a virtual environment. In the simulation, the CV90 vehicle, with its full dynamics, is driven over a specific virtual road at a particular velocity. The simulation itself cannot be manipulated; only the input values can be adjusted. Thus, we consider the simulation as a black box, which led us to implement the black-box optimization algorithm known as Particle-Swarm. In this thesis, four different roads, each with velocities ranging from four to seven different levels, were provided to the optimization model. The results show that the model identifies a combination of torsion bars that generates a small VDV for all combinations of velocities and roads, with an average VDV improvement of around 20% - 60% compared to a reference case. Since this thesis serves as a proof of concept, the conclusion is that the devised method is effective and suitable for addressing the problem at hand. Nonetheless, for seamless integration of this method into the tracked vehicle development process, further research is necessary.