Design of a six degree-of-freedom haptic hybrid platform manipultor

Thesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2010Includes bibliographical references (leaves: 97-103)Text in English; Abstract: Turkish and Englishxv, 115 leavesThe word Haptic, based on an ancient Greek word called haptios, means related with touch. As an area of robotics, haptics technology provides the sense of touch for robotic applications that involve interaction with human operator and the environment. The sense of touch accompanied with the visual feedback is enough to gather most of the information about a certain environment. It increases the precision of teleoperation and sensation levels of the virtual reality (VR) applications by exerting physical properties of the environment such as forces, motions, textures. Currently, haptic devices find use in many VR and teleoperation applications. The objective of this thesis is to design a novel Six Degree-of-Freedom (DOF) haptic desktop device with a new structure that has the potential to increase the precision in the haptics technology. First, previously developed haptic devices and manipulator structures are reviewed. Following this, the conceptual designs are formed and a hybrid structured haptic device is designed manufactured and tested. Developed haptic device.s control algorithm and VR application is developed in Matlab© Simulink. Integration of the mechanism with mechanical, electromechanical and electronic components and the initial tests of the system are executed and the results are presented. According to the results, performance of the developed device is discussed and future works are addressed

StandAlone Surgical Haptic Arm (SASHA)

A standalone surgical arm for performing Minimally Invasive Robotic Surgery (MIRS) with standard da Vinci Si tools has been developed. Force feedback is now possible with the feedback from torque sensors used to measure the forces acting upon the tool tip. The mechanical arm and a control system capable of driving the arm and reporting force information to the user via haptic feedback has been designed and fabricated. This arm will be used as a platform for research on the performance of telesurgery as a function of various haptic mappings and artificial latencies

Doctor of Philosophy

dissertationHumans generally have difficulty performing precision tasks with their unsupported hands. To compensate for this difficulty, people often seek to support or rest their hand and arm on a fixed surface. However, when the precision task needs to be performed over a workspace larger than what can be reached from a fixed position, a fixed support is no longer useful. This dissertation describes the development of the Active Handrest, a device that expands its user's dexterous workspace by providing ergonomic support and precise repositioning motions over a large workspace. The prototype Active Handrest is a planar computer-controlled support for the user's hand and arm. The device can be controlled through force input from the user, position input from a grasped tool, or a combination of inputs. The control algorithm of the Active Handrest converts the input(s) into device motions through admittance control where the device's desired velocity is calculated proportionally to the input force or its equivalent. A robotic 2-axis admittance device was constructed as the initial Planar Active Handrest, or PAHR, prototype. Experiments were conducted to optimize the device's control input strategies. Large workspace shape tracing experiments were used to compare the PAHR to unsupported, fixed support, and passive moveable support conditions. The Active Handrest was found to reduce task error and provide better speedaccuracy performance. Next, virtual fixture strategies were explored for the device. From the options considered, a virtual spring fixture strategy was chosen based on its effectiveness. An experiment was conducted to compare the PAHR with its virtual fixture strategy to traditional virtual fixture techniques for a grasped stylus. Virtual fixtures implemented on the Active Handrest were found to be as effective as fixtures implemented on a grasped tool. Finally, a higher degree-of-freedom Enhanced Planar Active Handrest, or E-PAHR, was constructed to provide support for large workspace precision tasks while more closely following the planar motions of the human arm. Experiments were conducted to investigate appropriate control strategies and device utility. The E-PAHR was found to provide a skill level equal to that of the PAHR with reduced user force input and lower perceived exertion

Sensorized Tools for Haptic Force Feedback in Computer Assisted Surgery

Structural engineerin

Design, control and evaluation of educational devices with series elastic actuation

STEM is a curriculum targeted to be used in all educational levels to support the education of students in four speci c disciplines{science, technology, engineering and mathematics{in an interdisciplinary and applied approach. Recently, as computational thinking and strong foundation in computing have been identi ed as de ning features that are likely to strongly shape the future, major research and development e orts have been put together to also promote computing by programs like STEM+C, where \C" further emphasizes computing. STEM+C not only aims to make the topics concerning these elds more understandable and enjoyable, but also to make them more accessible and a ordable for every group in the society. STEM+C promotes active learning, in other words, direct involvement of the student in class instead of passively listening, as an essential feature of an ideal learning environment and advocates for the use of technology and hands-on experience for strengthening the understanding of fundamental concepts. We propose HandsOn-SEA, a low cost, single degree-of-freedom, force-controlled educational robot with series elastic actuation, to enable physical interactions with educational tools, helping solidify STEM+C concepts. The novelty of the proposed educational robot design is due to the deliberate introduction of a compliant cross- exure pivot between the actuator and the handle, whose de ections are measured to estimate interaction forces and to perform closed-loop force control. As an admittance-type robot, HandsOn-SEA relies on a force control loop to achieve the desired level of safety and transparency during physical interactions and complements the existing impedance-type force-feedback educational robot designs. HandsOn-SEA also serves as a building block of more complex, higher degrees of freedom force-feedback robot designs. HandsOn-SEA is e ective in the education of STEM+C concepts, as physical interaction with virtual educational environments not only ensures a higher level of student engagement by adding new bi-directional sensorimotor pathway for active student perception, but also improves student motivation by enabling more engaging and exciting learning experiences. Furthermore, HandsOn-SEA allows for quantitative measurements of student progress and enables visually impaired students to bene t from a larger range of educational tools, by replacing certain visual presentations with haptic feedback. Along these lines, we present the integration of HandsOn-SEA into STEM+C education, by providing guidelines for the use of the device for teaching fundamental concepts in physical human-robot interaction (pHRI) at the undergraduate level and for teaching algorithmic thinking at both the high school and undergraduate levels. For pHRI education, we provide a set of laboratory modules with HandsOn-SEA to demonstrate the synergistic nature of mechanical design and control of force feedback devices. In particular, we propose and evaluate e cacy of a set of laboratory assignments that allow students to experience the performance trade-o s inherent in force control systems due to the non-collocation between the force sensor and the actuator. These exercises require students to modify the mechanical design in addition to the controller of the educational device by assigning di erent levels of sti ness values to its compliant element, and characterize the e ects of these design choices on the closed-loop force control performance of the device. We have evaluated the e cacy of introducing HandsOn-SEA into engineering education by testing the device in a senior level robotics course and provide evidence that the device is e ective in providing experience on admittance control architectures for pHRI and instilling intuition about fundamental trade-o s in the design and control of force-feedback devices. To promote algorithmic thinking, we propose to use force-feedback educational robotic devices for hands-on teaching of algorithms and present an interactive tool for teaching several sorting and search algorithms with such educational devices. The addition of haptic feedback to teach algorithmic thinking is advantageous as haptic feedback enables an e ective means of enforcing pairwise comparisons while ensuring data hiding, a key component in explaining several core concepts while teaching several sorting and search algorithms. Furthermore, physical interactions with virtual learning environments paves the way for more exible, engaging and exciting learning experiences, surpassing what can be achieved by basic physical elements or applications based on pure visualization. We have evaluated the e cacy of introducing haptic feedback into teaching algorithmic thinking by testing the proposed force-feedback application with several student groups and provide evidence that the approach is e ective in instilling the core principle of formulating a precise sequence of instructions for performing sorting tasks, in a technology independent manner

Haptics Rendering and Applications

There has been significant progress in haptic technologies but the incorporation of haptics into virtual environments is still in its infancy. A wide range of the new society's human activities including communication, education, art, entertainment, commerce and science would forever change if we learned how to capture, manipulate and reproduce haptic sensory stimuli that are nearly indistinguishable from reality. For the field to move forward, many commercial and technological barriers need to be overcome. By rendering how objects feel through haptic technology, we communicate information that might reflect a desire to speak a physically- based language that has never been explored before. Due to constant improvement in haptics technology and increasing levels of research into and development of haptics-related algorithms, protocols and devices, there is a belief that haptics technology has a promising future

Modeling of Force and Motion Transmission in Tendon-Driven Surgical Robots

Tendon-based transmission is a common approach for transferring motion and forces in surgical robots. In spite of design simplicity and compactness that comes with the tendon drives, there exists a number of issues associated with the tendon-based transmission. In particular, the elasticity of the tendons and the frictional interaction between the tendon and the routing result in substantially nonlinear behavior. Also, in surgical applications, the distal joints of the robot and instruments cannot be sensorized in most cases due to technical limitations. Therefore, direct measurement of forces and use of feedback motion/force control for compensation of uncertainties in tendon-based motion and force transmission are not possible. However, force/motion estimation and control in tendon-based robots are important in view of the need for haptic feedback in robotic surgery and growing interest in automatizing common surgical tasks. One possible solution to the above-described problem is the development of mathematical models for tendon-based force and motion transmission that can be used for estimation and control purposes. This thesis provides analysis of force and motion transmission in tendon-pulley based surgical robots and addresses various aspects of the transmission modeling problem. Due to similarities between the quasi-static hysteretic behavior of a tendon-pulley based da Vinci® instrument and that of a typical tendon-sheath mechanism, a distributed friction approach for modeling the force transmission in the instrument is developed. The approach is extended to derive a formula for the apparent stiffness of the instrument. Consequently, a method is developed that uses the formula for apparent stiffness of the instrument to determine the stiffness distribution of the tissue palpated. The force transmission hysteresis is further investigated from a phenomenological point of view. It is shown that a classic Preisach hysteresis model can accurately describe the quasi-static input-output force transmission behavior of the da Vinci® instrument. Also, in order to describe the distributed friction effect in tendon-pulley mechanisms, the creep theory from belt mechanics is adopted for the robotic applications. As a result, a novel motion transmission model is suggested for tendon-pulley mechanisms. The developed model is of pseudo-kinematic type as it relates the output displacement to both the input displacement and the input force. The model is subsequently used for position control of the tip of the instrument. Furthermore, the proposed pseudo-kinematic model is extended to compensate for the coupled-hysteresis effect in a multi-DOF motion. A dynamic transmission model is also suggested that describes system’s response to high frequency inputs. Finally, the proposed motion transmission model was used for modeling of the backlash-like hysteresis in RAVEN II surgical robot

Robotically assisted eye surgery : a haptic master console

Vitreo-retinal surgery encompasses the surgical procedures performed on the vitreous humor and the retina. A procedure typically consists of the removal of the vitreous humor, the peeling of a membrane and/or the repair of a retinal detachment. Operations are performed with needle shaped instruments which enter the eye through surgeon made scleral openings. An instrument is moved by hand in four degrees of freedom (three rotations and one translation) through this opening. Two rotations (? and ? ) are for a lateral instrument tip movement. The other two DoFs (z and ?) are the translation and rotation along the instrument axis. Actuation of for example a forceps can be considered as a fifth DoF. Characteristically, the manipulation of delicate, micrometer range thick intraocular tissue is required. Today, eye surgery is performed with a maximum of two instruments simultaneously. The surgeon relies on visual feedback only, since instrument forces are below the human detection limit. A microscope provides the visual feedback. It forces the surgeon to work in a static and non ergonomic body posture. Although the surgeon’s proficiency improves throughout his career, hand tremor may become a problem around his mid-fifties. Robotically assisted surgery with a master-slave system enhances dexterity. The slave with instrument manipulators is placed over the eye. The surgeon controls the instrument manipulators via haptic interfaces at the master. The master and slave are connected by electronic hardware and control software. Implementation of tremor filtering in the control software and downscaling of the hand motion allow prolongation of the surgeon’s career. Furthermore, it becomes possible to do tasks like intraocular cannulation which can not be done by manually performed surgery. This thesis focusses on the master console. Eye surgery procedures are observed in the operating room of different hospitals to gain insight in the requirements for the master. The master console as designed has an adjustable frame, a 3D display and two haptic interfaces with a coarse adjustment arm each. The console is mounted at the head of the operating table and is combined with the slave. It is compact, easy to place and allows the surgeon to have a direct view on and a physical contact with the patient. Furthermore, it fits in today’s manual surgery arrangement. Each haptic interface has the same five degrees of freedom as the instrument inside the eye. Through these interfaces, the surgeon can feel the augmented instrument forces. Downscaling of the hand motion results in a more accurate instrument movement compared to manually performed surgery. Together with the visual feedback, it is like the surgeon grasps the instrument near the tip inside the eye. The similarity between hand motion and motion of the instrument tip as seen on the display results in an intuitive manipulation. Pre-adjustment of the interface is done via the coarse adjustment arm. Mode switching enables to control three or more instruments manipulators with only two interfaces. Two one degree of freedom master-slave systems with force feedback are built to derive the requirements for the haptic interface. Hardware in the loop testing provides valuable insights and shows the possibility of force feedback without the use of force sensors. Two five DoF haptic interfaces are realized for bimanual operation. Each DoF has a position encoder and a force feedback motor. A correct representation of the upscaled instrument forces is only possible if the disturbance forces are low. Actuators are therefore mounted to the fixed world or in the neighborhood of the pivoting point for a low contribution to the inertia. The use of direct drive for ' and and low geared, backdriveable transmissions for the other three DoFs gives a minimum of friction. Disturbance forces are further minimized by a proper cable layout and actuator-amplifier combinations without torque ripple. The similarity in DoFs between vitreo-retinal eye surgery and minimally invasive surgery (MIS) enables the system to be used for MIS as well. Experiments in combination with a slave robot for laparoscopic and thoracoscopic surgery show that an instrument can be manipulated in a comfortable and intuitive way. User experience of surgeons and others is utilized to improve the haptic interface further. A parallel instead of a serial actuation concept for the ' and DoFs reduces the inertia, eliminates the flexible cable connection between frame and motor and allows that the heat of the motor is transferred directly to the frame. A newly designed z-?? module combines the actuation and suspension of the hand held part of the interface and has a three times larger z range than in the first design of the haptic interface

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 13th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2022, held in Hamburg, Germany, in May 2022. The 36 regular papers included in this book were carefully reviewed and selected from 129 submissions. They were organized in topical sections as follows: haptic science; haptic technology; and haptic applications