Over the past 20 years research into miniature actuators has been increasing. In addition to having a compact geometry, desirable characteristics for miniature actuators include having a large power-to-weight ratio, fast response, fine resolution of movement and high power efficiency. In the first part of this thesis the design of a miniature rotary robot joint is presented. Two single acting miniature cylinders each with a bore diameter of 4 mm drive the joint using water as the hydraulic fluid. The cylinders are mated to a rack and pinion mechanism that converts the opposing linear motion of the cylinders shafts into rotation. Also within the design, a novel position sensor using magnetic field sensing technology is presented. Overall, the joint measures 11 mm wide x 8.8 mm high x 150 mm long. In the second part of this thesis a hydraulic servo positioning system is presented along with a novel valve modeling technique and two position control strategies. Four low-cost, 3-way on/off solenoid valves were used to control the flow of the water in and out of the cylinders. The two nonlinear position controllers employed were a position-velocity-acceleration plus model-based feedforward controller (PVA+FF) and a novel PVA + FF plus sliding mode controller. For experiments involving horizontal rotation of the joint while carrying no load the PVA +FF controller achieved a steady-state error of ± 0.77° or ± 0.06 mm in terms of rack position. The steady-state error produced by the PVA + FF plus sliding mode controller was ± 0.85° or ± 0.07 mm. The maximum tracking error produced by both controllers was 5° or 0.41 mm and occurred during the initial cycloidal rising portion of a 120° displacement. The root mean square error (RMSE) of the PVA + FF and PVA + FF plus sliding mode controllers were 42% and 54% less than that produced by a linear PVA controller. Both controllers were found to be robust to changes in payload. This was experimentally verified by adding masses of 6.5 g and 13.5 g to the end of the output link of the joint. By conducting similar experiments in the vertical direction it was found that the PVA + FF plus sliding mode controller was more robust, achieving on average a 30% reduction in RMSE compared to the FF + PVA controller. / Thesis / Master of Applied Science (MASc)

The Heating, Ventilation and Air Conditioning (HVAC) systems are nowadays in almost every new building, develop or improve better control strategies for them is very common, looking to have more energy efficiency and require less input parameters from the user. In this project, new control strategies based in previous theory models has been used with a new approach in order to find a good solution for irregular occupied spaces. In this new approach a feed-forward filter with a fixed preheating time, using an algorithm based on an identified model, calculates how much degrees the temperature room can be decreased and regulate the power of the radiators to do it.The results of this project displays that the chosen model have to be changed but the idea is interesting, because the simulations of the reference building give, with a preheating timeof 2 hours, around 3ºC of temperature reduction during 18 days and savings of 33% of the heat energy needed for the whole month.Considering that buildings and the residential sector currently account for 40 percent of Sweden's energy consumption and around 25 percent of other countries like USA or Spain, and that irregular spaces are more or less a 10% of the governmental, institutional, academic or public buildings, the potential savings are not negligible. The evaluation of this control strategy with its mathematical model as well as its resultsduring the month of January and the behavior of the system along the year have been made with the help of IDA program for simulation of the reference building and its energy system.