Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 40-42). Also available in electronic version. Access restricted to campus users.

published_or_final_version / abstract / toc / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

The LaSalle Coke Tower is an existing structure located on a fifty-five foot strip of land bordering the south edge of the Lachine Canal and the north side of St. Patrick's St. (Montreal, Quebec). The railway passes through the structure at its base. Built at the turn of the century, the crane was used to hoist coal from barges to an elevated conveyor that carried it across the street to Cote-St.-Paul Gas Works. It is approximately 15 storeys high (167'). The Lachine Canal serviced the cause of industry from its completion in 1824 to the opening of the St. Lawrence Seaway in 1959 at which time industry slowly began to abandon the Lachine Canal area. The basic premise of the design project revolved around both preservation and development of Tour LaSalle Coke (LaSalle Coke Tower). Regarding preservation, it was the state of abandonment that was to be preserved, allowing for a sense of mobility, vagrant roving, free time, and liberty. Architectural production within the abandoned site must respond to the rhythms and flows of the passing of time and the loss of limits. The two principal components include a provision for discovery (architecture as a heuristic device) and an archive component housing historical documents relevant to the tower and it's surrounding context (the Lachine Canal). The essence of the project was to develop this type of site without destroying its character and without detracting from its historical significance. Careful consideration was essential to negotiate between development and preservation. A broader interpretation of heritage preservation was necessary: moving beyond the isolated monument to include territory which characterizes a particular place. In this instance tire place consisted of the extreme linear space of the canal and its adjacent properties in addition to the remnant architectural artifact of the tower. The state of abandonment is a part of the history of the site. The provision for discovery is made through the use of stairs and an elevator, allowing visitors uninhibited access to the tower. This provision allows for multiple levels of interaction with the artifact, from the short visit to a more comprehensive survey of the object. The archive component is a smallscale intervention thereby minimizing the impact of specialized components (or private spaces) which limit the sense of mobility, vagrant roving, free time and liberty. For the same reason, the food service and primary toilet facility is located 'off site' approximately 320 feet to the east. The goal was to retain the basic features of the artifact while providing for a means of discovery and documentation of a National Historic Landmark.

Machine vibration leads to lower precision, efficiency, and safety. As a result, large sums of money and innumerable man-hours are spent in efforts to reduce vibration in machinery. A subclass of machinery that is widely used in industry is two-mode flexible systems. Cranes with double-pendulum dynamics and two-link flexible robotic arms are representative examples of two-mode flexible systems. In order to thoroughly understand these types of systems, a detailed study of double-pendulum cranes is preformed. The crane payload is considered to be a distributed mass. The parameters of the payload and the crane has important effects on the dynamic response. the effects are studied as a function of the parameters so that effective control methods can be developed. This thesis develops a technique for improving the control of two-mode flexible systems called input shaping. Input shaping is a control strategy that uses a series of impulses to modify the reference command to suppress unwanted vibration in a system. This thesis reviews several types of input shapers and presents a method for optimizing a robust input shaper called Specified Insensitivity input shapers using knowledge of amplitude contributions of each mode to the overall response. Simulations and experiments are presented to verify the new algorithm. Two human operator studies are presented to demonstrate the effectiveness of input shaping when used in conjunction with distributed crane payloads, such as cargo containers. One study investigates the improvement in efficiency when using input shaping and the differences in efficiency between input shapers. The other study investigates operator learning when moving a payload with unshaped and shaped commands.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Singhose, William; Committee Member: Costello, Mark; Committee Member: Whiteman, Wayne

Thesis (M.S.)--Mississippi State University. Department of Industrial and Systems Engineering. / Title from title screen. Includes bibliographical references.

The LaSalle Coke Tower is an existing structure located on a fifty-five foot strip of land bordering the south edge of the Lachine Canal and the north side of St. Patrick's St. (Montreal, Quebec). The railway passes through the structure at its base. Built at the turn of the century, the crane was used to hoist coal from barges to an elevated conveyor that carried it across the street to Cote-St.-Paul Gas Works. It is approximately 15 storeys high (167'). The Lachine Canal serviced the cause of industry from its completion in 1824 to the opening of the St. Lawrence Seaway in 1959 at which time industry slowly began to abandon the Lachine Canal area. The basic premise of the design project revolved around both preservation and development of Tour LaSalle Coke (LaSalle Coke Tower). Regarding preservation, it was the state of abandonment that was to be preserved, allowing for a sense of mobility, vagrant roving, free time, and liberty. Architectural production within the abandoned site must respond to the rhythms and flows of the passing of time and the loss of limits. The two principal components include a provision for discovery (architecture as a heuristic device) and an archive component housing historical documents relevant to the tower and it's surrounding context (the Lachine Canal). The essence of the project was to develop this type of site without destroying its character and without detracting from its historical significance. Careful consideration was essential to negotiate between development and preservation. A broader interpretation of heritage preservation was necessary: moving beyond the isolated monument to include territory which characterizes a particular place. In this instance tire place consisted of the extreme linear space of the canal and its adjacent properties in addition to the remnant architectural artifact of the tower. The state of abandonment is a part of the history of the site. The provision for discovery is made through the use of stairs and an elevator, allowing visitors uninhibited access to the tower. This provision allows for multiple levels of interaction with the artifact, from the short visit to a more comprehensive survey of the object. The archive component is a smallscale intervention thereby minimizing the impact of specialized components (or private spaces) which limit the sense of mobility, vagrant roving, free time and liberty. For the same reason, the food service and primary toilet facility is located 'off site' approximately 320 feet to the east. The goal was to retain the basic features of the artifact while providing for a means of discovery and documentation of a National Historic Landmark. / Applied Science, Faculty of / Architecture and Landscape Architecture (SALA), School of / Graduate

This study examined the effect that pulse rate, pulse pattern, and onset distance had on the performance of an auditory warning signal. The warning signal's purpose was to alert mobile crane operators of their proximity to overhead power lines. The study consisted of two experimental phases. The first phase consisted of three sections; A) development and construction of the PWD's auditory warning signal. B) development of the experimental tasks and a pilot study, and C) an examination of the workload level of the secondary tracking task. Phase two consisted of a full factorial experiment which examined the performance effects caused by pulse rate range, pulse pattern, and onset distance manipulations. The experimental task required subjects to monitor an auditory warning system while simultaneously operating a single-axis driving simulation task. Subjects were required to initiate braking responses based on the information conveyed through the auditory collision warming system. In addition, subjective ratings were obtained to compare subjects’ actual performance using the warning system to their subjective preferences. Results indicate that subjects performed optimally under warning signals with moderate onset distances and low pulse rates. The pulse pattern did not have a large impact on subjects' performance across the various warning signals. Overall, it was concluded that a pulsing auditory warning signal comprised of a moderate onset distance and low pulse rate was subjectively preferred and would work effectively as a proximity warning device for mobile cranes. / Master of Science

Container cranes represent one of the most critical components of ports worldwide. Despite their importance to port operations, the seismic behavior of cranes has been largely ignored. Since the 1960s, industry experts have recommended allowing cranes to uplift, believing that it would limit the amount of seismic loading. However, modern cranes have become larger and more stable, and the industry experts are now questioning the seismic performance of modern jumbo cranes. The main goal of this research was to experimentally investigate the seismic behavior of container cranes from the general elastic behavior through collapse, including non-linear behavior such as buckling and cross section yielding, utilizing the 6 degree-of-freedom shake tables at the University at Buffalo. The testing was divided into two phases. The first phase of testing was conducted on a 1/20th scale model. The second phase of testing was conducted on a 1/10th scale model, which was designed such that no inelastic action would develop prior to uplift (as is the common design practice). In support of the experiments, finite element models were created to determine what simplifications could be made to the structure to aid in testing. The data collected from the testing has been used to validate finite element models, to give a better understanding of the behavior of container cranes under seismic excitations, validate fragility models, and to develop recommendations and guidelines for the design and testing of container cranes.

Cranes are widely used in material-handling and transportation applications, e.g. in shipyards, construction sites, and warehouses. As they are critical to the economic vitality of modern-day industries, improving crane performance and ease of use are important contributors to industrial productivity, low production costs, and workplace safety. In a typical crane operation, a payload is lifted, moved to its destination, and then lowered into place. This dissertation aims to improve crane performance and reduce task difficulty for the human operator in the movements mentioned above, namely: 1) Moving payloads laterally in the horizontal plane, 2) Lifting payloads off the ground, and 3) Lowering or laying down payloads on the ground. The design of a novel and intuitive human-machine control interface is the focus for improving operations that involve moving payloads laterally. The interface allows operators to drive a crane by simply moving a hand-held device through the desired path. The position of the device, which is tracked by sensors, is used to generate command signals to drive the crane. This command is then input-shaped such that payload oscillations are greatly reduced, making it much easier for the operator to drive the crane. Several facets of this crane control method are examined, such as control structure and stability, usability contexts, modes of operation, and quantitative measures (by means of human operator studies) of performance improvements over standard crane control interfaces. Lifting up a payload can be difficult for the operator, if the hoist is not properly centered above the payload. In these potentially dangerous and costly ``off-centered" lifts, the payload may slide on the ground and/or oscillate in the air after it is hoisted. Newtonian and Coulomb friction models that focus on the stiction-sliding-separation contact dynamics are derived and experimentally verified to study off-centered lifts. Then, with the goal of aiding operators during lift operations, simple but practical, self-centering solutions are proposed and implemented. Laying down or lowering a payload to the ground can also be challenging for operators in certain situations. For example, laying down a long, slender payload from a vertical orientation in the air, to a horizontal position on a flat surface. If the operator does not properly coordinate the motions of the crane in the vertical and horizontal directions simultaneously, then the potential hazards that may occur during these operations include: 1) slipping of the pivot about which the payload rotates, leading to sudden and dangerous payload movements; and 2) excessive hoist cable angles that lead to ``side-pull" problems. Newtonian and Coulomb friction models are derived to describe this lay-down scenario. The forces and motions experienced by the payload are then used to determine the motion trajectories that the crane and payload should follow to execute a successful lay-down maneuver. Finally, a special chapter is included to address the oscillation control of systems that have on-off nonlinear actuators, such as cranes powered by relay-controlled circuits. Due to their simplicity, ruggedness, and long service life, this type of crane can be commonly found in older factories or in applications where precise motion control is not a strict requirement. However, controlling payload oscillations on this type of crane is challenging for two reasons: 1) Relays that can only be turned on or off allow for only limited control over the crane velocity; and 2) These cranes typically have nonlinear asymmetrical acceleration and deceleration properties. Methods are derived for determining the relay switch-times that move single-pendulum and double-pendulum payloads with low residual oscillations.