Current robot manipulation and control paradigms have largely been developed for static or highly structured environments such as those common in factories. For most techniques in robot trajectory generation, such as heuristic-based geometric planning, this has led to putting a high cost on contact with the world. This approach and methodology can be prohibitive to robots operating in many unmodeled and dynamic environments. This dissertation presents work on using haptic based feedback (torque and tactile sensing) to formulate a controller for robot manipulation in clutter. We define “clutter” as any environment in which we expect the robot to make both incidental and purposeful contact while maneuvering and manipulating. The controllers developed in this dissertation take the form of single or multi-time step Model Predictive Control (a form of optimal control which incorporates feedback) which attempts to regulate contact forces at multiple locations on a robot arm while reaching to a goal. The results and conclusions in this dissertation are based on extensive testing in simulation (tens of thousands of trials) and testing in realistic scenarios with real robots incorporating tactile sensing. The approach is novel in the sense that it allows contact and explicitly incorporate the contact and predictive model of the robot arm in calculating control effort at every time step. The expected broader impact of this research is progress towards a new foundation of reactive feedback controllers that will include a higher likelihood of success in many constrained and dynamic scenarios such as reaching into containers without line of sight, maneuvering in cluttered search and rescue situations or working with unpredictable human co-workers.

Haptic simulation of medical procedures is an active area of research in engineering and medicine. Analogous to flight simulators for pilots, surgery simulators can allow medical students and doctors to practice procedures in a risk free and well monitored virtual environment. The quality of interaction that a surgery simulator can generate is dependent upon many components. In this thesis, careful attention is paid to the haptic display of viscous effects. / Viscous terms, defined here as terms that are dependent upon velocity, are typically computed 'using a discrete time backwards difference estimation of the velocity. It is well known that differentation has the tendency to amplify high frequency noise, and as a result, the backwards difference estimation generates considerable errors when applied to the quantized position readings from a digital encoder. Prior to this work, the only feasible method to improve velocity estimation was to use a variety of observation or filtering techniques, all of which inevitably add phase delay. In this thesis, the backwards difference operation was analyzed in detail. It was found that feedback viscosity simulation is very non-robust to noise, and oscillations exist in the presence of quantization noise regardless of the physical parameters of the plant. / A typical haptic interface for surgery simulation consists of a mechanical linkage driven by electric motors. These linkages are controlled with a computer using a discrete-time force update law that generates a prescribed force given the user's position in the medical virtual environment. It is clear from the literature that a haptic interface must have some level of physical dissipation to enable a passive rendering due to the inherent instability associated with time delayed systems. However, dissipation in typical haptic interfaces is a byproduct of their design, and is neither controllable nor easily identifiable. A prototype haptic interface is presented in this thesis that uses eddy current brakes to add high bandwidth programmable dissipation to an existing motor linkage. The new hardware has been optimized experimentally to maximize damping and minimize inertia given conventional machining and available material constraints. / A new paradigm in the control of haptic interfaces is time-domain passivity control. Passive systems are desirable in haptics because a passive system is globally stable, passivity theory applies to linear and nonlinear systems alike, and a user cannot extract energy from a passive system. Passivity controllers monitor the energy flow in the device and add virtual damping to remove any energy that violates the passivity constraint. Unfortunately, the amount of virtual damping available to a given device is limited by the physical dissipation that it exhibits. If the device is directly driven and light, such as the pantograph, the available virtual damping is insufficient to maintain the passivity constraint. The eddy current brakes allow programmable physical damping to be used in place of virtual damping which has been shown with experiments to improve the stable impedance range of a haptic interface. / It is clear from the literature that most tissues in a human body exhibit viscoelastic behavior. Simulation of viscoelastic objects requires that the velocity of interaction be known. Because typical haptic interfaces use digital encoders to sample position, the estimated velocity signal is noisy, delayed or both. Eddy current brakes are viscous actuators by nature, as they generate a resistive force proportional to the velocity. To take advantage of this fact, viscoelastic decomposition algorithms were developed that can output viscous components to the eddy current brakes and elastic components to the motors. This technique reduces or eliminates the use of a velocity estimation signal in the feedback loop which improves passivity, reduces motor saturation effects, and allows for a wider stable range of mechanical impedances than conventional haptic interfaces can achieve.

Following lower-limb amputation, patients suffer from sensory loss within the prosthesis/residuum complex leading to diminished proprioception and balance. Artificial sensory systems have the potential to improve rehabilitation outcomes including better functional usage of lower-limb prostheses to achieve a higher quality of life for the prosthetic users. The purpose of this work was to develop and test the e fficacy of a vibrotactile feedback system for lower-limb amputees that may augment feedback during complex balance and movement tasks. Responses to different vibrotactile stimuli frequencies, locations, and physical conditions were assessed. Key outcome measures for this work were the response time and response accuracy of the subjects to the different stimulator configurations. Frequencies closer to 250 Hz applied to the anterior portion of the thigh resulted in the quickest reaction times. When multitasking, reaction times increased. These preliminary results indicate that vibrotactile sensory feedback may be viable to use by lower-limb amputees.

Following lower-limb amputation, patients suffer from sensory loss within the prosthesis/residuum complex leading to diminished proprioception and balance. Artificial sensory systems have the potential to improve rehabilitation outcomes including better functional usage of lower-limb prostheses to achieve a higher quality of life for the prosthetic users. The purpose of this work was to develop and test the e fficacy of a vibrotactile feedback system for lower-limb amputees that may augment feedback during complex balance and movement tasks. Responses to different vibrotactile stimuli frequencies, locations, and physical conditions were assessed. Key outcome measures for this work were the response time and response accuracy of the subjects to the different stimulator configurations. Frequencies closer to 250 Hz applied to the anterior portion of the thigh resulted in the quickest reaction times. When multitasking, reaction times increased. These preliminary results indicate that vibrotactile sensory feedback may be viable to use by lower-limb amputees.

Affective haptic research is a rapidly growing field. Today, more smart haptic clothes are being studied and implemented which are aimed to effect its users emotionally. However, they have some limitations. This research intends to improve the existing literature and contribute by involving consumers directly in the design of a smart haptic jacket by adding heat, vibration actuators, and by enhancing portability. In this thesis, we are interested in six basic emotions: love, joy, surprise, anger, sadness, and fear. An online survey was designed and conducted on 92 respondents that gave feedback of what it is expected from an affective haptic jacket. The results of this survey assisted in the general design, and the feedback helped to build a prototype. 86% of the respondents expressed interest in the system and are willing to try it when it is ready. A detailed design architecture is provided along with details on the hardware and software used for the implementation. Finally, the prototype was evaluated on 14 participants using the actual prototype haptic jacket based on a QoE comparison between the absence and the presence of haptic actuation. The proposed system showed improvement over a similar system that is designed for the same purpose.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 153-162).

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 100-106).

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 112-118).

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [111]-119).

Submitted by THAYNÁ CRISTINA PARSANEZE IASI null (iasi_bob@hotmail.com) on 2018-04-02T22:08:10Z No. of bitstreams: 1 Thayná C. P. Iasi - Mestrado.pdf: 1856665 bytes, checksum: 1e364366bb33964d96f7f94ac51d39fd (MD5) / Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-04-03T11:57:09Z (GMT) No. of bitstreams: 1 iasi_tcp_me_rcla.pdf: 1628760 bytes, checksum: c369d0a3080f5a92e55e16e36f394378 (MD5) / Made available in DSpace on 2018-04-03T11:57:09Z (GMT). No. of bitstreams: 1 iasi_tcp_me_rcla.pdf: 1628760 bytes, checksum: c369d0a3080f5a92e55e16e36f394378 (MD5) Previous issue date: 2018-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Manter ou reestabelecer uma postura estável depende da detecção de informações por meio de sistemas sensoriais e sistemas de ação-percepção como o sistema háptico. O sistema háptico usa a exploração ativa inclusive durante o uso de ferramentas rígidas ou não rígidas para detectar propriedades importantes do ambiente. Um paradigma proposto sobre o papel do sistema háptico no controle da postura foi o sistema âncora. Os achados dos efeitos estabilizadores da postura com o uso do sistema âncora ilustram como o processo de detecção de informação do ambiente, distal ao corpo e mediado pela ferramenta âncora, depende da relação quase-estável no contato entre a superfície de apoio do corpo e a porção distal das âncoras. A extensão da utilidade desse contato distal para orientação postural ainda é pouco conhecida quanto ao contexto de perturbação da superfície. O objetivo do presente estudo foi investigar o papel da ancoragem realizada no próprio corpo, ou seja, com a porção distal em contato com quatro pontos corporais (i.e., cintura escapular, cintura, joelho e tornozelo), e verificar sua eficiência na redução da taxa de oscilação postural em contraste com a ancoragem tradicional (referência externa). Ainda, analisar a influência da localização desses pontos, distal ou proximal ao solo, quanto à função de ancoragem háptica. Para isso, foram testados 27 sujeitos ativos de ambos os sexos, que permaneceram imóveis em posição tandem sobre uma plataforma de força, com restrição da visão. As condições da tarefa de ancoragem incluíram: a ancoragem tradicional e ancoragem com conexão distal em contato com os quatro pontos corporais (cintura escapular, cintura, joelho e tornozelo). Foram analisadas as variáveis referentes à oscilação corporal (TT-CP, área da elipse, AMO-ML) e referentes à regulação da oscilação do centro de pressão (VM-ML). Os resultados obtidos demonstraram que a ancoragem nos pontos de contato corporal, via TT-CP e AMO-ML, reduziu a taxa de oscilação postural quando comparada à condição sem âncora. Entretanto, a âncora tradicional é mais eficiente do que quando a resistência vem da porção anexa em qualquer parte do corpo. Quando a comparação é feita entre os pontos de contato corporal, observamos que eles não diferem entre si. Concluímos que mesmo o contato de ancoragem no corpo sendo parcialmente eficiente na redução da taxa de oscilação corporal, este contexto não equipara aos níveis de redução de oscilação gerados por uma ancoragem com referência externa. / Maintaining or reestablishing a stable posture depends on the detection of information through sensory systems and action-perception systems such as the haptic system. The haptic system uses active exploration, even during the use of rigid and non-rigid tools used to detect important properties of the environment. A proposed paradigm about the role of the haptic system in posture control was the anchor system. The findings of the stabilizing effects of posture with the use of the anchor system demonstrate how the process of detecting information from the environment, distal to the body and mediated by the anchor tool, depends on the almost-stable relationship in the contact between body support surface and the distal portion of the anchors. The extent of the utility of this distal contact for postural orientation is still poorly known in the context of surface disturbance. The objective of the present study was to investigate the role of anchoring in own body, therefore, with the distal portion in contact with four corporal points (i.e., scapular waist, waist, knee and ankle), and verify the efficiency in reducing the rate of the postural oscillation in contrast to the traditional anchorage (external reference). Nevertheless, to analyze the influence of the location of these points, distal or proximal to the ground, regarding the function of haptic anchorage. For this, were tested 27 active subjects of both sexes, who remained immobile in a tandem position on a force platform, with visual restriction. The anchoring task conditions included: traditional anchorage and the anchorage with distal connection in contact with four body points (scapular waist, waist, knee, ankle). Were analyzed the variables related to body oscillation (TT-CP, ellipse area, OA-ML) and referring to regulation of the center of pressure oscillation (MD-ML). The results obtained showed that anchorage at the body contact points, via TT-CP and OA-ML, reduced the rate of postural oscillation when compared to non-anchor condition. However, the traditional anchor is more efficient than when the resistance comes from the attached portion in any part of the body When the comparison is made between the points of body contact, we observe that they do not differ from each other. We conclude that even the anchoring contact in the body being partially efficient in reducing the rate of body oscillation, this context does not equate to the levels of oscillation reduction generated by an anchorage with external reference.