Robot Builders

Many research teams around the world are building nanodevices of some kind. But these very small devices need very small sources of power to be fully functional. Now, researchers at the University of Illinois at Urbana-Champaign (UIUC) have shown that a single nanowire can produce power by harvesting mechanical energy from its environment. ‘Made of piezoelectric material, the nanowire generates a voltage when mechanically deformed.’ But don’t think that this nanowire, made of an oxide of barium and titanium, and measuring approximately 280 nanometers in diameter and 15 microns long, will be able to power anything more than a nanoscale sensor. It was able to generate an electrical energy of about 0.3 attojoules — less than one quintillionth of a joule or about 2.8E-25 kilowatt-hour. read story

This paper presents a time invariant kinematic motion controller for wheeled mobile robots. Actuator capability, mechanical design, and traction forces governed by terrain features provide velocity and curvature limitations that are used in the design of the controller. A novel path manifold that considers curvature limitations is introduced to provide a desired path shape and convergence to the reference posture or trajectory. Lyapunov techniques are then used to derive a control law that asymptotically converges the robot to an arbitrarily small neighborhood of the path manifold. Posture regulation, path following, and trajectory tracking capability to a similarly scaled neighborhood of the target are provided. Controller parameters are optimized and initial conditions are identified that satisfy physical constraints of the robot and provide smooth commands. Curvature boundaries and asymptotic convergence naturally limit allowable initial conditions and are resolved by driving the robot to intermediate goal points within regions of allowable initial conditions. Posture regulation is evaluated in simulation and experiment on a Compliant Framed wheeled Modular Mobile Robot (CFMMR) for two different terrain surfaces. Trajectory tracking and path following of constant curvature references are evaluated in simulation and experiment, respectively.

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The mobility sensors on a typical mobile robot vehicle have limited range. Therefore a navigation system has no knowledge about the world beyond this sensing horizon. As a result, path planners that rely only on this knowledge to compute paths are unable to anticipate obstacles sufficiently early and have no choice but to resort to an inefficient local obstacle avoidance behavior.

To alleviate this problem, we present an opportunistic navigation and view planning strategy that incorporates look-ahead sensing of possible obstacle configurations. This planning strategy is based on a “what-if” analysis of hypothetical future configurations of the environment. Candidate sensing positions are evaluated based on their ability to observe anticipated obstacles. These sensing positions identified by this forward-simulation framework are used by the planner as intermediate waypoints. The validity of the strategy is supported by results from simulations as well as field experiments with a real robotic platform. These results show that significant reduction in path length can be achieved by using this framework.

Compression algorithms are not really new, so I’ve looked cautiously at the work of U.S. computer scientists claiming that ‘they have developed technology that doubles the usable memory on cell phones and other embedded systems without any changes to hardware or applications.’ The CRAMES (Compressed RAM for Embedded Systems) technology uses the Linux kernel’s swapping mechanism to determine which pages should be compressed. According to the researchers, cell phones equipped with this technology don’t use more power than regular ones and show a very small performance loss. The first phone to use the CRAMES technology is sold by NEC — but only in Japan right now.

As one of the methods for reducing the work of programming, the Learning-from-Observation (LFO) paradigm has been heavily promoted. This paradigm requires the programmer only to perform a task in front of a robot and does not require expertise. In this paper, the LFO paradigm is applied to assembly tasks by two rigid polyhedral objects. A method is proposed for recognizing these tasks as a sequence of movement primitives from noise-contaminated data obtained by a conventional 6 degree-of-freedom (DOF) object-tracking system. The system is implemented on a robot with a real-time stereo vision system and dual arms with dexterous hands, and its effectiveness is demonstrated.

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The latest Talking Robots podcast interview is with Rudolf Bannasch, who seems to be single-handedly driving European research in Bionics. Professor at the Technical University in Berlin, Germany, coordinator of the German bionics competence network BIOKON, and founder of the startup company EvoLogics, he is a powerhouse of creativity when it comes to translating natural phenomena into engineering applications. He has studied penguins, mantas, dolphins and arctic birds, and then extracted key properties of these animals to optimize the performance of propellers, underwater modems, grippers, underwater vessels and aircraft (Turns out if you put penguins into wind-tunnels you are in for a real surprise - and yet another product for your startup!). Tune in for an overview of the state-of-the art and future in bionics, and for more information on Bannasch’s aqua-ray and air-ray robots, artificial penguins, or humanoid arms with fluidic muscles! -more-

Compression algorithms are not really new, so I’ve looked cautiously at the work of U.S. computer scientists claiming that ‘they have developed technology that doubles the usable memory on cell phones and other embedded systems without any changes to hardware or applications.’ The CRAMES (Compressed RAM for Embedded Systems) technology uses the Linux kernel’s swapping mechanism to determine which pages should be compressed. According to the researchers, cell phones equipped with this technology don’t use more power than regular ones and show a very small performance loss. The first phone to use the CRAMES technology is sold by NEC — but only in Japan right now.

Many algorithms have been proposed that create a path for a robot in an environment with obstacles. Most methods are aimed at finding a solution. However, for many applications, the path must be of a good quality as well. That is, a path should be short and should keep some amount of minimum clearance to the obstacles. Traveling along such a path reduces the chances of collisions due to the difficulty of measuring and controlling the precise position of the robot. This paper reports a new technique, called Partial shortcut, which decreases the path length. While current methods have difficulties in removing all redundant motions, the technique efficiently removes these motions by interpolating one degree of freedom at a time. Two algorithms are also studied that increase the clearance along paths. The first one is fast but can only deal with rigid, translating bodies. The second algorithm is slower but can handle a broader range of robots, including three-dimensional free-flying and articulated robots, which may reside in arbitrary high-dimensional configuration spaces. A big advantage of these algorithms is that clearance along paths can now be increased efficiently without using complex data structures and algorithms. Finally, we combine the two criteria and show that high-quality paths can be obtained for a broad range of robots.

The latest Talking Robots podcast interview is with Rudolf Bannasch, who seems to be single-handedly driving European research in Bionics. Professor at the Technical University in Berlin, Germany, coordinator of the German bionics competence network BIOKON, and founder of the startup company EvoLogics, he is a powerhouse of creativity when it comes to translating natural phenomena into engineering applications. He has studied penguins, mantas, dolphins and arctic birds, and then extracted key properties of these animals to optimize the performance of propellers, underwater modems, grippers, underwater vessels and aircraft (Turns out if you put penguins into wind-tunnels you are in for a real surprise - and yet another product for your startup!). Tune in for an overview of the state-of-the art and future in bionics, and for more information on Bannasch’s aqua-ray and air-ray robots, artificial penguins, or humanoid arms with fluidic muscles!