Wafer handling robotics are critical in semiconductor manufacturing to enable tight control of temperature, humidity, and particle contamination during processing. Closed-loop dynamic modeling during the robot design process ensures designs meet throughput and stability specifications prior to prototype hardware purchase. Dynamic models are also used in model-based control to improve performance. This thesis describes the generation and mathematical verification of a dynamic model for a three degrees-of-freedom wafer handling mechanism with one linear and two rotary axes. The dynamic plant model is integrated with motion and motor controller models, and the closed-loop performance is compared with experimental data. Models with rigid and flexible connections are compared, and the flexible connection models are shown to overall agree better with a measured step response. The simulation time increase from the addition of flexible connections can be minimized by modeling only the component stiffnesses that impact the closed-loop mechanism response. A method for selecting which elements to include based on controller bandwidth is presented and shown to significantly improve simulation times with minimal impact on model predictive performance.

<p>Agricultural tractors make massive use of hydraulic control technology. Being fuel con-sumption a big concern for agricultural applications, tractors typically use the state-of-the-art technology, load-sensing (LS) architecture, to allow good controllability in systems withmultiple actuators while promoting higher energy efficiency. Several variants of LS systemshave been proposed over the years, and research on cost-effective methods to further increasetheir efficiency is of high interest for original equipment manufacturers (OEMs) and the fluidpower community. In this work, several energy-efficient solutions are proposed and demon-strated for the reference agricultural tractor hydraulic system, aiming at reducing the fuelconsumption and increasing the system efficiency, but without affecting the functionalityof the hydraulic control system. More importantly, facing the more stringent regulationson the CO2emission and the rising consciousness of a greener environment in society, bothindustry and academia have investigated the use of electricity as energy carrier and storage.This report also carries out the study on the possibility of electrification of the referencemachine, focusing on the auxiliary hydraulic supply to the planter.</p> <p>To begin with, the quantification of the energy loss within the hydraulic system representsan important step to drive the development of cost-effective solutions. For this purpose, acombined approach of simulation and experimental testing has been undertaken to character-ize the power distribution in the high-pressure circuit. After learning that the remote controlvalves are responsible for up to 25% of power loss in the system, two different energy-efficientsolutions are proposed on the tractor circuit. Both methods target at lowering the pumpdelivery pressure through incorporating electronic proportional pressure reducing valves (ep-PRVs). To support the development of the technology, the research takes into considerationthe circuit of a 400 hp tractor, simulation and experimental results show that among themain working conditions the solution can reach up to 15.6% power saving over the standardLS system.</p> <p>Moreover, the primary purpose of a tractor is to providing power to and controllingvarious implements. Most of their mechanical actuation is performed also with the electro-hydraulic fluid power system that is highly power-dense and versatile, but that has a low energy transmission efficiency. A new control approach of the hydraulic supply units thatpower the implement functions through the hydraulic remote is proposed, which switches thetraditional flow control methodology to an impressed pressure methodology. With a 16-rowplanter connected to the tractor understudy, a simulation model of the two vehicles is imple-mented and validated against experiments. Experiments on the proposed solutions appliedto the reference tractor and planter confirmed how an overall 38% efficiency improvementwas achieved during actual tests.</p> <p>On top of the IPSC strategy, more intelligent control algorithm is explored by proposinga new system architecture to fully incorporate both of the LS pumps with all of the EHRs,to achieve dynamic regrouping control (DRC) or static regrouping control (SRC). The DRCalgorithm determines the best supply configuration to all of the functions with minimumpower loss in time, which eventually leads to 44% power reduction compared to the base-line. On the other hand, the SRC algorithm targets at providing the best planter groupinglayout when connected to the tractor supply to contribute to least throttling losses duringrepresentative planting operations. The restuls from the SRC configuration can serve as asuggestive layout for the OEM when promoting such machines to the market.</p> <p>Last but not least, different scenarios of both selective purely electrification architectureand selective e-pump supply architecture are considered to discover the potential futuredirection of electrification to follow for the reference machine. From the power saving pointof view, replacing the fertilizer and vacuum hydraulic motors with the electric ones couldlead to 72% power reduction from the engine. However, more study on the cost analysiscould be useful to balance the saving and the cost added in the system.</p>

Due to the detrimental effects of ride vibrations on occupants and increasing safety concerns, improvement in vehicle dynamic characteristics has become a key focus of researchers. Typically, ride and handling problems have been dealt with independently. There is a dearth of vehicle models capable of capturing occupant biodynamics and its implication on vehicle ride and handling. Also in general, the objective of conventional control systems has been to attenuate vertical dynamic response of the sprung mass of a vehicle. Feedback control based algorithms are predominantly used in active/semi-active suspensions that ignore the biodynamics of occupants. In the current work, a new 50 degree-of-freedom (DOF) combined nonlinear multi-occupant vehicle model is developed using the lumped parameter modelling (LPM) approach. The current model provides a platform for performing a combined study of ride, handling and occupant biodynamics. The model is capable of simulating the combined effect of sitting occupancies, road inputs and driving maneuvers on biodynamic responses. It is analyzed using MATLAB/SIMULINK functionalities and validated by independently correlating the computed responses with existing experimental results. A study is performed on ride behavior of a vehicle-occupant system under two different transient road inputs. In addition, the effect of road roughness on vehicle ride is also studied. Random road profiles are generated from road roughness spectrum given in the ISO 8608:1995 manual. Insights are developed into the ride dynamics of a vehicle traversing over roads of classes A, B, C and D at given test velocities. The effect of sitting occupancies and vehicle velocities on lateral dynamics is also studied. Results underscore the need for considering sitting occupancies while analyzing vehicle dynamics and also highlight the potential of the current model. Furthermore, a Moore-Penrose Pseudoinverse based feed-forward controller is developed and implemented in an independently acting semi-active seat suspension system. Feasibility of feed-forward control in primary suspensions is also investigated. Finally, issues of stability, performance and limitation of the controller are discussed.