Study on development of volume-controllable balloon with pressure sensing function and its application to surgical retractor

制度:新 ; 文部省報告番号:甲2652号 ; 学位の種類:博士(工学) ; 授与年月日:2008/3/24 ; 早大学位記番号:新481

Study on workspace-creation manipulator for minimally invasive surgery

制度:新 ; 文部省報告番号:甲2244号 ; 学位の種類:博士(工学) ; 授与年月日:2006/3/24 ; 早大学位記番号:新426

Development of Motion Control Systems for Hydraulically Actuated Cranes with Hanging Loads

Automation has been used in industrial processes for several decades to increase efficiency and safety. Tasks that are either dull, dangerous, or dirty can often be performed by machines in a reliable manner. This may provide a reduced risk to human life, and will typically give a lower economic cost. Industrial robots are a prime example of this, and have seen extensive use in the automotive industry and manufacturing plants. While these machines have been employed in a wide variety of industries, heavy duty lifting and handling equipment such as hydraulic cranes have typically been manually operated. This provides an opportunity to investigate and develop control systems to push lifting equipment towards the same level of automation found in the aforementioned industries. The use of winches and hanging loads on cranes give a set of challenges not typically found on robots, which requires careful consideration of both the safety aspect and precision of the pendulum-like motion. Another difference from industrial robots is the type of actuation systems used. While robots use electric motors, the cranes discussed in this thesis use hydraulic cylinders. As such, the dynamics of the machines and the control system designmay differ significantly. In addition, hydraulic cranes may experience significant deflection when lifting heavy loads, arising from both structural flexibility and the compressibility of the hydraulic fluid. The work presented in this thesis focuses on motion control of hydraulically actuated cranes. Motion control is an important topic when developing automation systems, as moving from one position to another is a common requirement for automated lifting operations. A novel path controller operating in actuator space is developed, which takes advantage of the load-independent flow control valves typically found on hydraulically actuated cranes. By operating in actuator space the motion of each cylinder is inherently minimized. To counteract the pendulum-like motion of the hanging payload, a novel anti-swing controller is developed and experimentally verified. The anti-swing controller is able to suppress the motion from the hanging load to increase safety and precision. To tackle the challenges associated with the flexibility of the crane, a deflection compensator is developed and experimentally verified. The deflection compensator is able to counteract both the static deflection due to gravity and dynamic de ection due to motion. Further, the topic of adaptive feedforward control of pressure compensated cylinders has been investigated. A novel adaptive differential controller has been developed and experimentally verified, which adapts to system uncertainties in both directions of motion. Finally, the use of electro-hydrostatic actuators for motion control of cranes has been investigated using numerical time domain simulations. A novel concept is proposed and investigated using simulations.publishedVersio

Modeling and Testing of Docking and Berthing Mechanisms

The Contact Dynamics Simulation Laboratory (CDSL) of the Marshall Space Flight Center provides for refined hardware-in-the-loop real-time simulation of docking and berthing mechanisms and associated control systems. This facility is employed to verify the performance of docking/berthing mechanisms during Earth-orbit operations, determine the capture envelope of dockingherthing devices, measure contact loads at vehicle interfaces, and evaluate visual cues for man-in-the-loop operations. The CDSL has developed test verified analytical models of such systems as the ISS Common Berthing Mechanism and HST Three Point Docking Mechanism. This paper will describe the modeling and test techniques employed at the CDSL and present results from recent programs

Improving Automated Operations of Heavy-Duty Manipulators with Modular Model-Based Control Design

The rapid development of robotization and automation in mobile working machines aims to increase productivity and safety in many industrial sectors. In heavy-duty applications, hydraulically actuated manipulators are the common solution due to their large power-to-weight ratio. As hydraulic systems can exhibit nonlinear dynamic behavior, automated operations with closed-loop control become challenging. In industrial applications, the dexterity of operations for manipulators is ensured by providing interfaces to equip product variants with different tool attachments. By considering these domain-specific tool attachments for heavy-duty hydraulic manipulators (HHMs), the autonomous robotic operating development for all product variants might be a time-consuming process. This thesis aims to develop a modular nonlinear model-based (NMB) control method for HHMs to enable systematic NMB model reuse and control system modularity across different HHM product variants with actuators and tool attachments. Equally importantly, the properties of NMB control are used to improve the high-performance control for multi degrees-of-freedom robotic HHMs, as rigorously stability-guaranteed control systems have been shown to provide superior performance. To achieve these objectives, four research problems (RPs) on HHM controls are addressed. The RPs are focused on damping control methods in underactuated tool attachments, compensating for static actuator nonlinearities, and, equally significantly, improving overall control performance. The fourth RP is introduced for hydraulic series elastic actuators (HSEAs) in HHM applications, which can be regarded as supplementing NMB control with the aim of improving force controllability. Six publications are presented to investigate the RPs in this thesis. The control development focus was on modular NMB control design for HHMs equipped with different actuators and tool attachments consisting of passive and actuated joints. The designed control methods were demonstrated on a full-size HHM and a novel HSEA concept in a heavy-duty experimental setup. The results verified that modular control design for HHM systems can be used to decrease the modifications required to use the manipulator with different tool attachments and floating-base environments

Chip-on-tip endoscope incorporating a soft robotic pneumatic bending microactuator.

In the ever advancing field of minimally invasive surgery, flexible instruments with local degrees of freedom are needed to navigate through the intricate topologies of the human body. Although cable or concentric tube driven solutions have proven their merits in this field, they are inadequate for realizing small bending radii and suffer from friction, which is detrimental when automation is envisioned. Soft robotic actuators with locally actuated degrees of freedom are foreseen to fill in this void, where elastic inflatable actuators are very promising due to their S3-principle, being Small, Soft and Safe. This paper reports on the characterization of a chip-on-tip endoscope, consisting out of a soft robotic pneumatic bending microactuator equipped with a 1.1 × 1.1 mm2 CMOS camera. As such, the total diameter of the endoscope measures 1.66 mm. To show the feasibility of using this system in a surgical environment, a preliminary test on an eye mock-up is conducted

Offshore Wind Turbine Access Using Knuckle Boom Cranes

Doktorgradsavhandling, Fakultet for teknologi og realfag, Institutt for ingeniørvitenskap, 2016There is a great need for renewable and sustainable energy today and there are several different sources for this energy where offshore wind is one that has a great estimated planned power production. Wind power production has for many years been produced onshore, but installing the wind turbines offshore has some benefits due to higher and more stable wind conditions. The majority of installed wind turbines are today bottom fixed, but when moving to deeper waters it is too high cost in building and installing foundation, which brings the possibility of using floating wind turbines. There are, however, also challenges due to the access for both the fixed and floating offshore wind turbines. During startup, repair or maintenance there is a demand for easy access of both personnel and equipment. This dissertation mainly deals with offshore access solutions systems or parts of those systems. The access solutions are systems that transfers personnel or equipment from a floating vessel to a fixed or floating offshore structure. Work done using a small scale hydraulic manipulator is described in Papers A and B, where paper A deals with the kinematic motion control of such a small scale redundant manipulator mounted on a moving Stewart platform, imitating the motion of a floating vessel. The manipulator tries to keep the tool point at a fixed reference point by the use of the pseudo-inverse Jacobian. Used in the experimental verification is a high precision laser tracker which measures the position of the tool point. Paper B uses the same manipulator and has in addition a hanging payload attached to the tool point. A LQR control strategy is used to minimize the vibration of the hanging payload when the manipulator moves the tool point relative to a ground fixed coordinate system. Paper C is concerned with the inherent oscillatory nature of pressure compensated motion control of a hydraulic cylinder subjected to a negative load and suspended by means of a counter-balance valve. The method proposed in this paper has the focus on pressure feedback and is compared to classical control strategies. In paper D input shaping is used for the slewing motion control of a full scale mobile crane. The flexibility of the crane causes vibrations when slewing and by knowing the natural frequency and damping, the command signal is shaped so there are no residual vibrations. Experimental verification is carried out by means of a laser tracker. Finally, the work done in Paper E deals with active heave compensation from a fixed structure to a floating vessel. Modeling of the hydraulic winch is done and a frequency response function is obtained. The active heave compensation was experimentally verified using the full scale mobile crane as the fixed structure with a winch mounted on it and the Stewart platform as the moving structure. Both results from active heave compensation and constant tension are presented. The payload in the experiments is a 400kg steel structure