A scheme is developed for classifying the types of motion perceived by a humanlike robot. It is assumed that the robot receives visual images of the scene using a perspective system model. Equations, theorems, concepts, clues, etc., relating the objects, their positions, and their motion to their images on the focal plane are presented. >

http://ieeexplore.ieee.org/iel2/815/3148/00100651.pdf

Robot vision

Traditional robots have rigid underlying structures that limit their ability to interact with their environment. For example, conventional robot manipulators have rigid links and can manipulate objects using only their specialised end effectors. These robots often encounter difficulties operating in unstructured and highly congested environments. A variety of animals and plants exhibit complex movement with soft structures devoid of rigid components. Muscular hydrostats e.g. octopus arms and elephant trunks are almost entirely composed of muscle and connective tissue and plant cells can change shape when pressurised by osmosis. Researchers have been inspired by biology to design and build soft robots. With a soft structure and redundant degrees of freedom, these robots can be used for delicate tasks in cluttered and/or unstructured environments. This paper discusses the novel capabilities of soft robots, describes examples from nature that provide biological inspiration, surveys the state of the art and outlines existing challenges in soft robot design, modelling, fabrication and control.

/pdf/soft-robotics-biological-inspiration-state-of-the-art-and-1esuws0p9g.pdf

Soft robotics: Biological inspiration, state of the art, and future research

Mobile robot vision-based navigation has been the source of countless research contributions, from the domains of both vision and control. Vision is becoming more and more common in applications such as localization, automatic map construction, autonomous navigation, path following, inspection, monitoring or risky situation detection. This survey presents those pieces of work, from the nineties until nowadays, which constitute a wide progress in visual navigation techniques for land, aerial and autonomous underwater vehicles. The paper deals with two major approaches: map-based navigation and mapless navigation. Map-based navigation has been in turn subdivided in metric map-based navigation and topological map-based navigation. Our outline to mapless navigation includes reactive techniques based on qualitative characteristics extraction, appearance-based localization, optical flow, features tracking, plane ground detection/tracking, etc... The recent concept of visual sonar has also been revised.

Visual Navigation for Mobile Robots: A Survey

Closeup exploration of underwater life requires new forms of interaction, using biomimetic creatures that are capable of agile swimming maneuvers, equipped with cameras, and supported by remote human operation. Current robotic prototypes do not provide adequate platforms for studying marine life in their natural habitats. This work presents the design, fabrication, control, and oceanic testing of a soft robotic fish that can swim in three dimensions to continuously record the aquatic life it is following or engaging. Using a miniaturized acoustic communication module, a diver can direct the fish by sending commands such as speed, turning angle, and dynamic vertical diving. This work builds on previous generations of robotic fish that were restricted to one plane in shallow water and lacked remote control. Experimental results gathered from tests along coral reefs in the Pacific Ocean show that the robotic fish can successfully navigate around aquatic life at depths ranging from 0 to 18 meters. Furthermore, our robotic fish exhibits a lifelike undulating tail motion enabled by a soft robotic actuator design that can potentially facilitate a more natural integration into the ocean environment. We believe that our study advances beyond what is currently achievable using traditional thruster-based and tethered autonomous underwater vehicles, demonstrating methods that can be used in the future for studying the interactions of aquatic life and ocean dynamics.

Exploration of underwater life with an acoustically controlled soft robotic fish

Underwater images are affected by reduced contrast and non-uniform colour cast due to the absorption and scattering of light in the aquatic environment. This affects the quality and reliability of image processing and therefore colour correction is a necessary pre-processing stage. In this paper, we propose an Unsupervised Colour Correction Method (UCM) for underwater image enhancement. UCM is based on colour balancing, contrast correction of RGB colour model and contrast correction of HSI colour model. Firstly, the colour cast is reduced by equalizing the colour values. Secondly, an enhancement to a contrast correction method is applied to increase the Red colour by stretching red histogram towards the maximum (i.e., right side), similarly the Blue colour is reduced by stretching the blue histogram towards the minimum (i.e., left side). Thirdly, the Saturation and Intensity components of the HSI colour model have been applied for contrast correction to increase the true colour using Saturation and to address the illumination problem through Intensity. We compare our results with three well known methods, namely Gray World, White Patch and Histogram Equalisation using Adobe Photoshop. The proposed method has produced better results than the existing methods.

http://www.mcs.csueastbay.edu/~grewe/pubs/DistSensorNetworkBook2011/ImageProcess/UnderWaterImageEnhancement.pdf

Enhancing the low quality images using Unsupervised Colour Correction Method

AQUA, an amphibious robot that swims via the motion of its legs rather than using thrusters and control surfaces for propulsion, can walk along the shore, swim along the surface in open water, or walk on the bottom of the ocean. The vehicle uses a variety of sensors to estimate its position with respect to local visual features and provide a global frame of reference

http://vgrserver.cse.yorku.ca/~jenkin/papers/2007/ieeecomputer.pdf

AQUA: An Amphibious Autonomous Robot

We describe recent results obtained with AQUA, a mobile robot capable of swimming, walking and amphibious operation. Designed to rely primarily on visual sensors, the AQUA robot uses vision to navigate underwater using servo-based guidance, and also to obtain high-resolution range scans of its local environment. This paper describes some of the pragmatic and logistic obstacles encountered, and provides an overview of some of the basic capabilities of the vehicle and its associated sensors. Moreover, this paper presents the first ever amphibious transition from walking to swimming.

/pdf/a-visually-guided-swimming-robot-4jbreqkc7k.pdf

A visually guided swimming robot

This paper describes an underwater walking robotic system being developed under the name AQUA, the goals of the AQUA project, the overall hardware and software design, the basic hardware and sensor packages that have been developed, and some initial experiments. The robot is based on the RHex hexapod robot and uses a suite of sensing technologies, primarily based on computer vision and INS, to allow it to navigate and map clear shallow-water environments. The sensor-based navigation and mapping algorithms are based on the use of both artificial floating visual and acoustic landmarks as well as on naturally occurring underwater landmarks and trinocular stereo.

/pdf/aqua-an-aquatic-walking-robot-1fo4oftajr.pdf

AQUA: an aquatic walking robot

Consistent image mosaicking is a potentially useful tool for robot navigation and map construction. This paper presents an automatic algorithm to generate consistent image mosaicking. During the robot processing, local optimization based on the related previous images is used for every newly added image on the baseline approach view. As soon as a loop is detected, a global optimization method is activated to generate a globally consistent image mosaicking. This method is very efficient in computation and storage saving

http://web.cs.dal.ca/~eem/cvWeb/pubs/ROBIO-332-imageMosaic.pdf

Graph-based Automatic Consistent Image Mosaicking

Accurate localization for underwater robot is a big challenge in the mobile robot community. We use acoustic and visual-based approaches to solve the problem. In this paper, we focuses on the artificial landmark visual-based localization. The robot carries the camera to localize its position by calculating the camera's viewpoint through looking at the landmarks. The position of landmarks is known in a world-centered coordinate system (WCCS). A method is presented in this paper to recover the camera's viewpoint with minimum three feature points and a single image from one camera. Two steps are used in this paper: first step is to calculate the feature points' 3D coordinates in a camera centered coordinate system (CCCS); second step is to obtain a closed-form solution through the geometric transformations to map the 3D points from CCCS to WCCS. The algorithm is robust and efficient. It uses the fewest feature points required so far to deal with the same problem

http://web.cs.dal.ca/~eem/cvWeb/pubs/ROBIO-67-location.pdf

Pifu Zhang

Papers

AQUA: An Amphibious Autonomous Robot

A visually guided swimming robot

AQUA: an aquatic walking robot

Graph-based Automatic Consistent Image Mosaicking

Underwater Robot Localization using Artificial Visual Landmarks