7,244 research outputs found
Design and implementation of a sensor testing system with use of a cable drone
Abstract. This thesis aims to develop a testing method for various sensors by modifying a commercial cable cam system to drive with an automated process at constant speed. The goal is to find a way to lift the cables in the air securely without a need for humans to climb on ladders and place them afterwards. This is achieved with a hinged truss tower structure that keeps the cables stabile while the tower is lifted. Another goal was to achieve automated movement of the cable drone. This is done by connecting a tracking camera to a computer that is used to control the cable drone’s motor controller. This will have the drone behave in a certain way depending on the tracking camera’s position data. Third goal is to build a portable sensor system which collects and saves the data from the tested sensors. This goal is achieved with an aluminium profile frame which is equipped with all the necessary equipment, such as a powerful computer.
Research included studying different sensors’ performance evaluation criteria and effect of the wind on magnitude of the force in this application. Research was done by studying written sources and consulting a cable camera company called Motion Compound GbR. Results of this master’s thesis are used to evaluate if the idea of using a cable cam is applicable for this kind of sensor testing system. As the conclusion the cable drone with automated driving is evaluated to be a practical method which can still be further developed to meet the requirements even better. Antureiden testausjärjestelmän suunnittelu ja toteuttaminen käyttäen vaijeridronea. Tiivistelmä. Tämän diplomityön tavoitteena on muokata kaupallisesta vaijerikamerajärjestelmästä vakionopeudella liikkuva testausmenetelmä eri antureille. Yhtenä työn tavoitteena on löytää tapa nostaa käytettävät vaijerit ylös turvallisesti siten, ettei niitä tarvitse asentaa jälkikäteen korkealla. Tämä toteutetaan saranoidulla, trusseista rakennetulla tornilla. Tornin huipulle asennetaan laakeroidut akselit sekä suoja, jotka yhdessä pitävät vaijerit paikoillaan myös tornin noston ajan. Toinen tavoite on saavuttaa vaijerilennokin automatisoitu liike. Tämä tapahtuu kytkemällä seurantakamera tietokoneeseen, jota käytetään ohjaamaan myös vaijeridronen moottoriohjainta. Näin vaijeridrone saadaan käyttäytymään halutulla tavalla riippuen seurantakameran sijaintitiedoista. Kolmas tavoite on rakentaa kannettava anturijärjestelmä, jolla kerätään ja tallennetaan testatuilla antureilla kerätty data. Tämä tavoite saavutetaan alumiiniprofiilirungolla, joka varustetaan tarvittavilla laitteilla, kuten esimerkiksi tehokkaalla tietokoneella. Tutkimukseen kuului myös antureiden suorituskyvyn arviointikriteereihin tutustuminen sekä työssä käytettävästä järjestelmästä koituvan voiman suuruuden laskeminen. Tutkimus tehtiin perehtymällä kirjallisuuteen ja konsultoimalla vaijerikamera-alalla toimivaa Motion Compound GbR -yritystä. Tämän diplomityön tuloksia voidaan hyödyntää arvioitaessa, onko vaijerikamerajärjestelmä sovellettavissa mainitun anturien testausjärjestelmän rakentamisessa. Lopputuloksena automatisoidulla ajolla varustetun vaijeridronen arvioidaan olevan tähän tarkoitukseen toimiva menetelmä, jota voidaan edelleen kehittää vastaamaan vaatimuksia vielä paremmin
Overcoming barriers and increasing independence: service robots for elderly and disabled people
This paper discusses the potential for service robots to overcome barriers and increase independence of
elderly and disabled people. It includes a brief overview of the existing uses of service robots by disabled and elderly
people and advances in technology which will make new uses possible and provides suggestions for some of these new
applications. The paper also considers the design and other conditions to be met for user acceptance. It also discusses
the complementarity of assistive service robots and personal assistance and considers the types of applications and
users for which service robots are and are not suitable
ShapeClip: towards rapid prototyping with shape-changing displays for designers
This paper presents ShapeClip: a modular tool capable of transforming any computer screen into a z-actuating shape-changing display. This enables designers to produce dynamic physical forms by "clipping" actuators onto screens. ShapeClip displays are portable, scalable, fault-tolerant, and support runtime re-arrangement. Users are not required to have knowledge of electronics or programming, and can develop motion designs with presentation software, image editors, or web-technologies. To evaluate ShapeClip we carried out a full-day workshop with expert designers. Participants were asked to generate shape-changing designs and then construct them using ShapeClip. ShapeClip enabled participants to rapidly and successfully transform their ideas into functional systems
Powered Transtibial Prosthetic Device Control System Design, Implementation and Testing
A powered lower limb prosthesis, which consists of a four bar mechanism, a torsional spring and a brushed DC motor, was previously designed and fabricated. To regulate the motor power input, a two level controller was proposed and built. The control algorithm includes a higher level finite state controller and lower level PID controllers. To implement the control system, a digital signal processor (DSP) control board and MATLAB Simulink were used to realize the higher level control and a DC motor controller was used to realize the lower level PID control. Sensors were selected to provide the required feedback. The entire control system was implemented on a convenient to carry backpack. Amputee subject testing was performed to obtain some experimental verification of the design. The results showed that the control system performed consistently with the designed control algorithm and did assist in the amputee’s walking. Compared to a currently available powered prosthesis, this control is simple in structure and able to mimic the nonlinear behavior of the ankle closely
A HoloLens Application to Aid People who are Visually Impaired in Navigation Tasks
Day-to-day activities such as navigation and reading can be particularly challenging for people with visual impairments. Reading text on signs may be especially difficult for people who are visually impaired because signs have variable color, contrast, and size. Indoors, signage may include office, classroom, restroom, and fire evacuation signs. Outdoors, they may include street signs, bus numbers, and store signs. Depending on the level of visual impairment, just identifying where signs exist can be a challenge. Using Microsoft\u27s HoloLens, an augmented reality device, I designed and implemented the TextSpotting application that helps those with low vision identify and read indoor signs so that they can navigate text-heavy environments. The application can provide both visual information and auditory information. In addition to developing the application, I conducted a user study to test its effectiveness. Participants were asked to find a room in an unfamiliar hallway. Those that used the TextSpotting application completed the task less quickly yet reported higher levels of ease, comfort, and confidence, indicating the application\u27s limitations and potential in providing an effective means to navigate unknown environments via signage
Software for Wearable Devices: Challenges and Opportunities
Wearable devices are a new form of mobile computer system that provides
exclusive and user-personalized services. Wearable devices bring new issues and
challenges to computer science and technology. This paper summarizes the
development process and the categories of wearable devices. In addition, we
present new key issues arising in aspects of wearable devices, including
operating systems, database management system, network communication protocol,
application development platform, privacy and security, energy consumption,
human-computer interaction, software engineering, and big data.Comment: 6 pages, 1 figure, for Compsac 201
Development of a Wearable Mechatronic Elbow Brace for Postoperative Motion Rehabilitation
This thesis describes the development of a wearable mechatronic brace for upper limb rehabilitation that can be used at any stage of motion training after surgical reconstruction of brachial plexus nerves. The results of the mechanical design and the work completed towards finding the best torque transmission system are presented herein. As part of this mechatronic system, a customized control system was designed, tested and modified. The control strategy was improved by replacing a PID controller with a cascade controller. Although the experiments have shown that the proposed device can be successfully used for muscle training, further assessment of the device, with the help of data from the patients with brachial plexus injury (BPI), is required to improve the control strategy. Unique features of this device include the combination of adjustability and modularity, as well as the passive adjustment required to compensate for the carrying angle
On improving control and efficiency of a portable pneumatically powered ankle-foot orthosis
Ankle foot orthoses (AFOs) are widely used as assistive and/or rehabilitation devices to correct gait of people with lower leg neuromuscular dysfunction and muscle weakness. An AFO is an external device worn on the lower leg and foot that provides mechanical assistance at the ankle joint. Active AFOs are powered devices that provide assistive torque at the ankle joint. We have previously developed the Portable Powered Ankle-Foot Orthosis (PPAFO), which uses pneumatic power via compressed CO2 to provide untethered ankle torque assistance. My dissertation work focused on the development of control strategies for the PPAFO that are robust, applicable to different gait patterns, functional in different gait modes, and energy efficient. Three studies addressing these topics are presented in this dissertation: (1) estimation of the system state during the gait cycle for actuation control; (2) gait mode recognition and control (e.g., stair and ramp descent/ascent); and (3) system analysis and improvement of pneumatic energy efficiency.
Study 1 presents the work on estimating the gait state for powered AFO control. The proposed scheme is a state estimator that reliably detects gait events while using only a limited array of sensor data (ankle angle and contact forces at the toe and heel). Our approach uses cross-correlation between a window of past measurements and a learned model to estimate the configuration of the human walker, and detects gait events based on this estimate. The proposed state estimator was experimentally validated on five healthy subjects and with one subject that had neuromuscular impairment. The results highlight that this new approach reduced the root-mean-square error by up to 40% for the impaired subject and up to 49% for the healthy subjects compared to a simplistic direct event controller. Moreover, this approach was robust to perturbations due to changes in walking speed and control actuation.
Study 2 proposed a gait mode recognition and control solution to identify a change in walking environment such as stair and ramp ascent/descent. Since portability is a key to the success of the PPAFO as a gait assist device, it is critical to recognize and control for multiple gait modes (i.e., level walking, stair ascent/descent and ramp ascent/descent). While manual mode switching is implemented on most devices, we propose an automatic gait mode recognition scheme by tracking the 3D position of the PPAFO from an inertial measurement unit (IMU). Experimental results indicate that the controller was able to identify the position, orientation and gait mode in real time, and properly control the actuation. The overall recognition success rate was over 97%.
Study 3 addressed improving operational runtime by analyzing the system efficiency and proposing an energy harvesting and recycling scheme to save fuel. Through a systematic analysis, the overall system efficiency was determined by deriving both the system operational efficiency and the system component efficiency. An improved pneumatic operation utilized an accumulator to harvest and then recycle the exhaust energy from a previous actuation to power the subsequent actuation. The overall system efficiency was improved from 20.5% to 29.7%, a fuel savings of 31%. Work losses across pneumatic components and solutions to improve them were quantified and discussed.
Future work including reducing delay in recognition, exploring faulty recognition, additional options for harvesting human energy, and learning control were proposed
Exploring human-object interaction through force vector measurement
Thesis: S.M., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2019Cataloged from PDF version of thesis.Includes bibliographical references (pages 101-107).I introduce SCALE, a project aiming to further understand Human-Object Interaction through the real-time analysis of force vector signals, which I have defined as "Force-based Interaction" in this thesis. Force conveys fundamental information in Force-based Interaction, including force intensity, its direction, and object weight - information otherwise difficult to be accessed or inferred from other sensing modalities. To explore the design space of force-based interaction, I have developed the SCALE toolkit, which is composed of modularized 3d-axis force sensors and application APIs. In collaboration with big industry companies, this system has been applied to a variety of application domains and settings, including a retail store, a smart home and a farmers market. In this thesis, I have proposed a base system SCALE, and two additional advanced projects titled KI/OSK and DepthTouch, which build upon the SCALE project.by Takatoshi Yoshida.S.M.S.M. Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Science
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