Atlas Copco Surface Drilling Equipment is one of the leading manufacturers of surface drill rigs. To stay in the top segment it is of great importance to have a well functioning development strategy as well as rig functions that makes the work as easy as possible for the operator. In this master thesis one development strategy has been evaluated and a dub tip control has been developed from idea to test on rig.   Today the conventional method to position the drill is to use two joysticks with three axes each where each axis corresponds to one hydraulic actuator on the boom and feeder structure. The dub tip control system enables the operator to position the drill in Cartesian coordinates with only one 3-axes joystick. After the definition of the desired drill angle is done, the control system makes sure that this angle is obtained throughout the positioning motion. This system makes it considerably easier for an inexperienced operator to position the drill.   For development, simulation and verification of the control algorithms and regulators Matlab/Simulink has been used. To test the control system on rig, a configuration with LabVIEW together with a compactDAQ has been evaluated. LabVIEW is chosen because it provides the opportunity to create a user friendly graphical user interface. To use this configuration is however not recommended for persons with little or none experience from using LabVIEW.   This development strategy can be used for tests and verifications of control algorithms, but since neither Windows nor the compactDAQ are real time systems, there are solutions that are better but of course to a higher price.   The master thesis work has shown that it is possible to implement a dub tip control on a rig of this dimension. It has also concluded that compensated valves are necessary to achieve optimal performance of a velocity controlled dub tip positioning.

Robotic automation has been the major driving force in modern industrial developments. High speed pick-and-place operations find their place in many manufacturing applications. The goal of this project is to develop a class of high speed robots that has a planar workspace. The presented robots are intended for pick-and-place applications that have a relatively large workspace. In order to achieve this goal, the robots must be both stiff and light. The design strategies adapted in this study were expanded from the research work by Prof Khajepour and Dr. Behzadipour. The fundamental principles are to utilize a parallel mechanism to enhance robot stiffness and cable construction to reduce moving inertia. A required condition for using cable construction is the ability to hold all cables under tension. This can only be achieved under certain conditions. The design phase of the study includes a static analysis on the robot manipulator that ensures certain mechanical components are always held under tension. This idea is extended to address dynamic situations where the manipulator velocity and acceleration are bounded. Two concept robot configurations, 2D-Deltabot, and 2D-Betabot are presented. Through a series of analyses from the robot inverse kinematic model, the dynamic properties of a robot can be computed in an effective manner. It was determined that the presented robots can achieve 4g acceleration and 4m/s maximum speed within their 700mm by 100mm workspace with a pair of 890W rotary actuators controlling two degrees of freedom. The 2D-Deltabot was chosen for prototype development. A kinematics calibration algorithm was developed to enhance the robot accuracy. Experimental test results had shown that the 2D-Deltabot was capable of running at 81 cycles per minute on a 730mm long pick-and-place path. Further experiments showed that the robot had a position accuracy of 0. 62mm and a position repeatability of 0. 15mm, despite a few manufacturing errors from the prototype fabrication.

Modular and Reconfigurable Robots (MRRs) are those designed to address the increasing demand for flexible and versatile manipulators in manufacturing facilities. The term, modularity, indicates that they are constructed by using a limited number of interchangeable standardized modules which can be assembled in different kinematic configurations. Thereby, a wide variety of specialized robots can be built from a set of standard components. The term, reconfigurability, implies that the robots can be disassembled and rearranged to accommodate different products or tasks rather than being replaced. A set of MRR modules may consist of joints, links, and end-effectors. Different kinematic configurations are achieved by using different joint, link, and end-effector modules and by changing their relative orientation. The number of distinct kinematic configurations, attainable by a set of modules, varies with respect to the size of the module set from several tens to several thousands. Although determining the most suitable configuration for a specific task from a predefined set of modules is a highly nonlinear optimization problem in a hybrid continuous and discrete search space, a solution to this problem is crucial to effectively utilize MRRs in manufacturing facilities. The objective of this thesis is to develop novel optimization methods that can effectively search the Kinematic Configuration (KC) space to identify the most suitable manipulator for any given task. In specific terms, the goal is to develop and synthesize fast and efficient algorithms for a Task-Based Configuration Optimization (TBCO) from a given set of constraints and optimization criteria. To achieve such efficiency, a TBCO solver, based on Memetic Algorithms (MA), is proposed. MAs are hybrids of Genetic Algorithms (GAs) and local search algorithms. MAs benefit from the exploration abilities of GAs and the exploitation abilities of local search methods simultaneously. Consequently, MAs can significantly enhance the search efficiency of a wide range of optimization problems, including the TBCO. To achieve more optimal solutions, the proposed TBCO utilizes all the solutions of the Inverse Kinematics(IK) problem. Another objective is to develop a method for incorporating the multiple solutions of the IK problem in a trajectory optimization framework. The output of the proposed trajectory optimization method consists of a sequence of desired tasks and a single IK solution to reach each task point. Moreover, the total cost of the optimized trajectory is utilized in the TBCO as a performance measure, providing a means to identify kinematic configurations with more efficient optimized trajectories. The final objective is to develop novel IK solvers which are both general and complete. Generality means that the solvers are applicable to all the kinematic configurations which can be assembled from the available module inventory. Completeness entails the algorithm can obtain all the possible IK solutions.

Researchers who study pointing facilitation have identified the ability to identify--during motion--the likely target of a user's pointing gesture, as a necessary precursor to pointing facilitation in modern computer interfaces. To address this need, we develop and analyze how an understanding of the underlying characteristics of motion can enhance our ability to predict the target or endpoint of a goal-directed movement in graphical user interfaces. Using established laws of motion and an analysis of users' kinematic profiles, we demonstrate that the initial 90% of motion is primarly balistic and submovements are limited to the last 10% of gesture movement. Through experimentation, we demonstrate that target constraint and the intended use of a target has either a minimal effect on the motion profile or affects the last 10% of motion. Therefore, we demonstrate that any technique that models the intial 90% of gesture motion will not be affected by target constraint or intended use. Given, these results, we develop a technique to model the initial ballistic motion to predict user endpoint by adopting principles from the minimum jerk principle. Based on this principle, we derive an equation to model the initial ballistic phase of movement in order to predict movement distance and direction. We demonstrate through experimentation that we can successfully model pointing motion to identify a region of likely targets on the computer display. Next, we characterize the effects of target size and target distance on prediction accuracy. We demonstrate that there exists a linear relationship between prediction accuracy and target distance and that this relationship can be leveraged to create a probabilistic model for each target on the computer display. We then demonstrate how these probabilities could be used to enable pointing facilitation in modern computer interfaces. Finally, we demonstrate that the results from our evaluation of our technique are supported by the current motor control literature. In addition, we show that our technique provides optimal accuracy for any optimal accuracy when prediction of motion endpoint is performed using only the ballistic components of motion and before 90% of motion distance.

The adaptation of inverse dynamics was performed to quantitatively examine the subtle locomotor changes, previously undetectable, in rodent locomotion following nervous system injury. The first experiment performed an injury with known effects, a unilateral lesion of the medial and lateral branches of the left tibial nerve of Long-Evans rats, and measured the resulting data via inverse dynamics. Special effort was made to account for skin movement artefacts using a global optimization method for marker digitization. The second experiment attempted to apply this technique to Long-Evans rats with spinal hemisections at spinal level T-10. After the peripheral nerve injury to the tibial nerve branches, the main findings were that ankle joint still produces an extensor moment and positive power without the active contraction of the gastrocnemius m. It is possible that this phenomenon is due to passive contractile elements of the muscle and tendon. In addition, the knee and hip of the lesion leg stiffen, resulting in substantial reductions in moment generation and nearly total losses of both negative and positive power production. There were also compensations made by the opposite hindlimb and contralateral forelimb. The spinal cord hemisection produced subtle, complicated intra and interlimb changes in both joint moment and joint power analysis that could not be seen by looking at joint angles alone.

Linearized stability analysis methodologies, system identification algorithms and optimal control approaches that are applicable to large scale, flexible multibody dynamic systems are presented in this thesis. For stability analysis, two classes of closely related algorithms based on a partial Floquet approach and on an autoregressive approach, respectively, are presented in a common framework that underlines their similarity and their relationship to other methods. The robustness of the proposed approach is improved by using optimized signals that are derived from the proper orthogonal modes of the system. Finally, a signal synthesis procedure based on the identified frequencies and damping rates is shown to be an important tool for assessing the accuracy of the identified parameters; furthermore, it provides a means of resolving the frequency indeterminacy associated with the eigenvalues of the transition matrix for periodic systems. For system identification, a robust algorithm is developed to construct subspace plant models. This algorithm uniquely combines the methods of minimum realization and subspace identification. It bypasses the computation of Markov parameters because the free impulse response of the system can be directly computed in the present computational environment. Minimum realization concepts were applied to identify the stability and output matrices. On the other hand, subspace identification algorithms construct a state space plant model of linear system by using computationally expensive oblique matrix projection operations. The proposed algorithm avoids this burden by computing the Kalman filter gain matrix and model dependency on external inputs in a small sized subspace. Balanced model truncation and similarity transformation form the theoretical foundation of proposed algorithm. Finally, a forward innovation model is constructed and estimates the input-output behavior of the system within a specified level of accuracy. The proposed system identification algorithms are computationally inexpensive and consist of purely post processing steps that can be used with any multi-physics computational tool or with experimental data. Optimal control methodologies that are applicable to comprehensive large-scale flexible multibody systems are presented. A classical linear quadratic Gaussian controller is designed, including subspace plant identification, the evaluation of linear quadratic regulator feedback gain and Kalman filter gain matrices and online control implementation.

This work is initiated from an observation of the rolling-sliding kinematic behavior observed in the motion of the knee joint. We use the slip ratio as a parameter to analyze the rolling-sliding properties of a mechanism, and also propose a method to design new mechanisms with specific slip ratio. In this research, we first verify the many definitions of the slip ratio, then modify a best definition to suit various rolling-sliding motions. Most importantly, we propose two types of rolling-sliding mechanism design. By changing the parameters of the mechanism, we can adjust its slip ratio curve to be close to a desired curve. In addition, when the idea of adjustable link length is used in the design of the mechanism, exact slip ratio curve as specified can be generated by the use of some cams.

Kinematic analysis of basketball shooting is evolving, however the effects of fatigue on free throw shooting have not been studied. Therefore the effects of fatigue on the kinematics of free throw shooting among elite male basketball players was assessed. Ten healthy male collegiate basketball players participated in the study. Resting and fatigue heart rates of the participants were measured. After a 15 minute warm-up period, markers were placed on seven locations on the shooting arm&rsquo / s side upper and lower extremities. The free throw shots were recorded with two digital cameras at a speed of 60 frames/s at a stereoscopic position. Data were analyzed with the photogrammetry technique. Each participant performed free throw shots (pre-fatigue condition) until the two successful and two unsuccessful shots were collected. Then participants completed a fatigue protocol, which included sprints and squat jumping, until reaching their volitional exhaustion and free throw shots were repeated (post-fatigue condition). The elbow, trunk, knee and ankle joint angles were measured. Successful and unsuccessful shots were compared for pre- and post-fatigue conditions. The results demonstrated that fatigue did not affect free throw shooting and there was no significant joint angle difference (p&gt / .05) between successful and unsuccessful shots (p&gt / .05). It was concluded that fatigue does not affect the kinematics of free throw shooting of healthy male collegiate basketball players and there were no differences in the kinematics of selected joint angles for successful and unsuccessful free throw shots.

Locomotion is a key characteristic of almost all forms of life and is often accomplished, whether on land, in water, or in the air, by reciprocal motion of two or more appendages. Among the zooplankton, many species propel themselves by rhythmically beating multiple pairs of closely spaced leg-like appendages in a back-to-front (metachronal) pattern. The focus of this study is to understand the mechanical design, kinematic operation, and hydrodynamic result of metachrony in the zooplankton. In the first part of this study, Antarctic krill (Euphausia superba) are investigated as an ecologically important model species that metachronally beats its swimming legs (pleopods) to perform drag-based propulsion. Based on high speed videos of freely swimming Antarctic krill, hovering, fast forward swimming, and upside down swimming are identified as three distinct swimming modes with significantly different stroke amplitudes and beat frequencies. When transitioning between hovering and fast forward swimming, Antarctic krill first increase beat amplitude and secondarily increase beat frequency. In considering the design components that contribute to metachrony being a successful swimming technique, a comparison among many different species shows that the ratio between the appendage separation distance and appendage length is limited to a narrow range of values (i.e. 0.2 - 0.65). In the second part of this study, metachrony is examined at smaller length and time scales by examining the impulsive escape jump of a calanoid copepod (Calanus finmarchicus). The wake generated by the copepod's metachronally beating swimming legs is experimentally measured using a novel (and newly developed) tomographic particle image velocimetry (PIV) system capable of making volumetric 3D velocity measurements with high temporal and spatial resolution using IR illumination. The flow generated by the escaping copepod consisted of a stronger posterior vortex ring generated by the metachronally stroking swimming legs and a weaker one generated anteriorly around the body by the impulsive start of the escape, both of which decayed over time. The experiments also revealed azimuthal asymmetry in the vortices caused by body yawing and the action of the swimming legs, flow features not considered in previous axisymmetric computational and theoretical models of copepod jumps. While not accounting for this asymmetry, an impulsive stresslet is nonetheless useful in modeling the flow created by the escaping copepod and represents the flow more accurately than an impulsive Stokeslet. In the final part of this study, the flow associated with metachronal hovering in Antarctic krill is experimentally and theoretically investigated in regards to the energy requirements of the pelagic lifestyle. Volumetric flow measurements of a hovering Antarctic krill show that each stroking pleopod drags flow behind it such that a downward stream develops medially. The lateral exopodites induce tip vortices which add to the lift force on each appendage. Furthermore, the flow beneath the hovering krill develops into a pulsed jet with a Strouhal number in the 'high-efficiency zone' of 0.2 < St < 0.4. Actuator disk theory is used to make theoretical estimates of the induced power necessary to hover, the results of which match induced power values calculated from measured flow gradients contributing to viscous energy dissipation.

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