Hydraulophone design considerations : absement, displacement, and velocity-sensitive music keyboard in which each key is a water jet

We present a musical keyboard that is not only velocity-sensitive, but in fact responds to absement (presement), displacement (placement), velocity, acceleration, jerk, jounce, etc. (i.e. to all the derivatives, as well as the integral, of displacement). Moreover, unlike a piano keyboard in which the keys reach a point of maximal displacement, our keys are essentially infinite in length, and thus never reach an end to their key travel. Our infinite length keys are achieved by using water jet streams that continue to flow past the fingers of a person playing the instrument. The instrument takes the form of a pipe with a row of holes, in which water flows out of each hole, while a user is invited to play the instrument by interfering with the flow of water coming out of the holes. The instrument resembles a large flute, but, unlike a flute, there is no complicated fingering pattern. Instead, each hole (each water jet) corresponds to one note (as with a piano or pipe organ). Therefore, unlike a flute, chords can be played by blocking more than one water jet hole at the same time. Because each note corresponds to only one hole, different fingers of the musician can be inserted into, onto, around, or near several of the instrument’s many water jet holes, in a variety of different ways, resulting in an ability to independently control the way in which each note in a chord sounds. Thus the hydraulophone combines the intricate embouchure control of woodwind instruments with the polyphony of keyboard instruments. Various forms of our instrument include totally acoustic, totally electronic, as well as hybrid instruments that are acoustic but also include an interface to a multimedia computer to produce a mixture of sounds that are produced by the acoustic properties of water screeching through orific plates, as well as synthesized sounds

An embedded implementation of Bayesian network robot programming methods

A wide variety of approaches exist for dealing with uncertainty in robotic reasoning, but relatively few consider the propagation of statistical information throughout an entire robotic system. The concept of Bayesian Robot Programming (BRP) involves making decisions based on inference into probability distributions, but can be complex and difficult to implement due to the number of priors and random variables involved. In this work, we apply Bayesian network structures to a modified BRP paradigm to provide intuitive structure and simplify the programming process. The use of discrete random variables in the network can allow high inference speeds, and an efficient programming toolkit suitable for use on embedded platforms has been developed for use on mobile robots. A simple example of navigational reasoning for a small mobile robot is provided as an example of how such a network can be used for probabilistic decisional programming

Autonomous micro-rovers for future planetary exploration and terrestrial sensing

Autonomous Robotic vehicles represent a key and fast-moving technology area in space exploration and exploitation. We aim to to make future operations on other planets more affordable, reliable, and responsive by developing better and more useful mobile robots that can be deployed on other planets, and expediting this process by applying similar technologies to robotic applications on Earth. These robots must be responsive, energy efficient, lightweight for transport, and mechanically robust. To accomplish these goals, we have developed the Aria micro-rover platform based on micro-rover concepts for low-cost Mars surface and subsurface exploration and inspired by the recent resurgence of interest in planetary exploration. The Aria is designed using a novel methodology for probabilistic autonomy programming that makes use of Bayesian networks for highly reliable sensor fusion, planning, and behaviour control. Autonomy and AI are accomplished by inference-based reasoning into stored probabilistic data, and includes probabiliistic learning and self-programming. A fully distributed electronic component architecture with fault tolerance increases modularity and adaptability. Reliability is maximized and cost of deployment is minimized by modularly re-using common hardware and components. Also, the mechanical structure uses a lightweight and flexible actuated space frame to increase resiliency and allow full-body movements. The use of flexible structures allows the rover to transform and re-configure itself to a limited extent in the field. The physical design is driven by the need for light weight, simplicity and reconfigurability, with a minimalist mechanical structure and a flexible software design model to facilitate additions and multiple use cases. To lower cost of construction and transport, mass is minimized through the use of thin structural members and wire members in tension to create resilience without adding additional material. The Aria platform is unique in its aim to be constructed using as much automation as possible during manufacture. The chassis makes use of a jointed frame that can be assembled using additive manufacturing methods. The electronics are common modules that are attached and connected during the manufacturing process using a common bus architecture and later programmed for component-specific duties. The mission responsiveness of the platform is very high due to the ability to re-use and re-configure modules as needed for mission changes. This also opens the possibility for rovers to be mass-produced and deployed autonomously, or even assembled on another planet by using local materials to save transport of mass. In addition to the ability to be deployed as a planetary rover for scientific or resource management use, the Aria rover is targeted at terrestrial applications by using similar but non space qualified electronics to lower cost and increase availability. The primary applications targeted are 1) agricultural field monitoring and intervention, 2) environmental sensing and research uses, and 3) surveillance and disaster response. The Aria rover platform represents a new paradigm in deploying mobile robots to perform remote missions on Earth and other planets. Prototypes are currently being tested, and the technologies refined to produce more reliable, responsive, and flexible configurations for the applications of the future

Non-destructive measurement of stress using ultrasonic leaky lamb waves

This paper examines non-destructive measurement of stress using ultrasonic leaky lamb wave

A concept study of small planetary rovers : using Tensegrity Structures on Venus

Venus is among the most enigmatic and interesting places to explore in the solar system. However, the surface of Venus is a very hostile, rocky environment with extreme temperatures, pressures, and chemical corrosivity. A planetary rover to explore the surface would be scientifically valuable, but must use unconventional methods in place of traditional robotic control and mobility. This study proposes that a tensegrity structure can provide adaptivity and control in place of a traditional mechanism and electronic controls for mobility on the surface of Venus and in other extreme environments. Tensegrity structures are light and compliant, being constructed from simple repeating rigid and flexible members and stabilized only by tension, drawing inspiration from biology and geometry, and are suitable for folding, deployment, and adaptability to terrain. They can also utilize properties of smart materials and geometry to achieve prescribed movements. Based on the needs of scientific exploration, a simple tensegrity rover can provide mobility and robustness to terrain and environmental conditions, and can be powered by environmental sources such as wind. A wide variety of tensegrity structures are possible, and some initial concepts suitable for volatile and complex environments are proposed here

A low cost photodiode sun sensor for CubeSat and planetary micro-rover

This paper presents the development of low-cost methodologies to determine the attitude of a small, CubeSat-class satellite and a microrover relative to the sun's direction. The use of commercial hardware and simple embedded designs has become an effective path for university programs to put experimental payloads in space for minimal cost, and the development of sensors for attitude and heading determination is often a critical part. The development of two compact and efficient but simple coarse sun sensor methodologies is presented in this research. A direct measurement of the solar angle uses a photodiode array sensor and slit mask. Another estimation of the solar angle uses current measurements from orthogonal arrays of solar cells. The two methodologies are tested and compared on ground hardware. Testing results show that coarse sun sensing is efficient even with minimal processing and complexity of design for satellite attitude determination systems and rover navigation systems

Ultrasonic amplitude fitting of fibre orientation in fibre-reinforced polymers

This paper focuses on ultrasonic amplitude fitting of fibre orientation in fibre-reinforced polymer

Study for femto satellites using micro control moment gyroscope

Abstract— Femto-satellites can be used for distributed space missions that can require hundreds to thousands of satellites for real time, distributed, multi-point networks to accomplish remote sensing and science objectives. While suitable sensors are available using micro-electro-mechanical system technology, most femto-satellite designs have no attitude control capability due to the power and size constraints on attitude control actuators. A novel femto-satellite design that uses a micro-electro-mechanical system Control Moment Gyroscope is studied in this paper. We focus on the principal design, modelling, and discussion of the proposed Control Moment Gyroscope while detailing a controllable femto-satellite design that can make use of attitude control for simple sensing missions

Planetary micro-rover operations on Mars using a Bayesian framework for inference and control

With the recent progress toward the application of commercially-available hardware to small-scale space missions, it is now becoming feasible for groups of small, efficient robots based on low-power embedded hardware to perform simple tasks on other planets in the place of large-scale, heavy and expensive robots. In this paper, we describe design and programming of the Beaver micro-rover developed for Northern Light, a Canadian initiative to send a small lander and rover to Mars to study the Martian surface and subsurface. For a small, hardware-limited rover to handle an uncertain and mostly unknown environment without constant management by human operators, we use a Bayesian network of discrete random variables as an abstraction of expert knowledge about the rover and its environment, and inference operations for control. A framework for efficient construction and inference into a Bayesian network using only the C language and fixed-point mathematics on embedded hardware has been developed for the Beaver to make intelligent decisions with minimal sensor data. We study the performance of the Beaver as it probabilistically maps a simple outdoor environment with sensor models that include uncertainty. Results indicate that the Beaver and other small and simple robotic platforms can make use of a Bayesian network to make intelligent decisions in uncertain planetary environments

Autonomous navigation with ROS for a mobile robot in agricultural fields

Autonomous monitoring of agricultural farms and fields has recently become feasible due to continuing advances in robotics technology, but many notable challenges remain. In this paper, we describe the state of ongoing work to create a fully autonomous ground rover platform for monitoring and intervention tasks on modern farms that is built using inexpensive and off the shelf hardware and Robot Operating System (ROS) software so as to be affordable to farmers. The hardware and software architectures used in this rover are described along with challenges and solutions in odometry and localization, object recognition and mapping, and path planning algorithms under the constraints of the current hardware. Results obtained from laboratory and field testing show both the key challenges to be overcome, and the current successes in applying a low-cost rover platform to the task of autonomously navigating the outdoor farming environment