A survey of non-prehensible pneumatic manipulation surfaces : principles, models and control.

International audienceMany manipulation systems using air flow have been proposed for object handling in a non-prehensile way and without solid-to-solid contact. Potential applications include high-speed transport of fragile and clean products and high-resolution positioning of thin delicate objects. This paper discusses a comprehensive survey of state-of-the-art pneumatic manipulation from the macro scale to the micro scale. The working principles and actuation methods of previously developed air-bearing surfaces, ultra-sonic bearing surfaces, air-flow manipulators, air-film manipulators, and tilted air-jet manipulators are reviewed with a particular emphasis on the modeling and the control issues. The performance of the previously developed devices are compared quantitatively and open problems in pneumatic manipulation are discussed

Taking the First Step Toward Autonomous Quadruped Robots: The Quadruped Robot Challenge at ICRA 2023 in London [Competitions]

Last year, the IEEE Robotics and Automation Society (RAS) CAB Competition Committee proposed the Quadruped Robot Challenge (QRC) as an exemplary robot challenge organized by RAS at RAS’s major conferences. As a part of the project, the first version of the QRC was held in ICRA 2023 in London. In this column, we would like to introduce the challenges and the results

Direct measurement of mechanical vibrations of the 4-rod RFQ at the HLI

In this paper, we present a new haptic interface, called active skin , which is configured with a tactile sensor and a tactile stimulator in single haptic cell, and multiple haptic cells are embedded in a dielectric elastomer. The active skin generates a wide variety of haptic feel in response to the touch by synchronizing the sensor and the stimulator. In this paper, the design of the haptic cell is derived via iterative analysis and design procedures. A fabrication method dedicated to the proposed device is investigated and a controller to drive multiple haptic cells is developed. In addition, several experiments are performed to evaluate the performance of the active skin

Distributed manipulation using naturally existing force fields.

Many distributed manipulation systems are capable of generating planar force fields that act over the entire surface of an object to manipulate it to a stable equilibrium within the field. Passive air flow and other physical phenomena naturally generate force fields via linear superposition of logarithmically varying radial potential fields. The main advantage of these fields is that they are realizable through very simple actuation. However, they do not lend themselves to analytical prediction of net forces or equilibria. In this thesis, I present a distributed manipulation system with naturally existing passive force fields. First, I develop theoretical backgrounds to understand properties of naturally existing passive force fields such as the logarithmic force field of air flow. I present an efficient means of numerically computing the net force and moment exerted by such fields on objects composed of multiple simple shapes, as well as efficient means of finding equilibrium points on these fields. The second part concerns manipulation issues. Based on the analysis of the first part, I propose two possible manipulation concepts. One concept is a direct application of potential field combinations. With proper combinations of flow sinks, one can predict the equilibrium point efficiently so as to place an object at a certain position with known orientation. I propose a squeeze-like sequential manipulation using relatively simple flow fields to bring an object with a unique pivot point to a unique pose. A numerical analysis is provided to check the uniqueness of an object pivot point. The other proposed manipulation concept is to manipulate an object against a stationary barrier. Frictional contact mechanics in a logarithmic potential force field is studied and an algebraic representation is employed to study orientation controllability of the manipulation system. Experimental implementations demonstrate the feasibility of manipulation using logarithmic potential force fields.Ph.D.Applied SciencesMechanical engineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/125453/2/3192732.pd

Predicting the Size of Spring Network Swarm in Quadratic Potential Fields

Abstract- Formation control of multiple autonomous agents or a swarm of robots have become popular in robotics. Formation control is to maintain specific connections among multiple autonomous robots while performing tasks such as traversing trajectories, exploring environments, or covering spaces. We assume that robots are virtually connected by Delaunay triangulation, which is a general form of acute angle connection. This virtual connection forms a spring network, and we find tight upper bounds of the swarm size when we apply quadratic potential fields to the group of robots for the position and formation control. We present a method of Delaunay triangulation using circle bounds. By assuming hexagonal shape of each cell of swarm connection, we present a method of predicting a tight size of an ellipse that encircles the swarm

Development of a Wheel-Type In-Pipe Robot Using Continuously Variable Transmission Mechanisms for Pipeline Inspection

Pipelines are embedded in industrial sites and residential environments, and maintaining these pipes is crucial to prevent leakage. Given that most pipelines are buried, the development of robots capable of exploring their interiors is essential. In this work, we introduce a novel in-pipe robot utilizing Continuously Variable Transmission (CVT) mechanisms for navigating various pipes, including vertical and curved pipes. The robot comprises one air motor, three CVT mechanisms, and six wheels at the end of six slider-crank mechanisms, including three active and three idler ones. The slider crank and spring mechanism generate a wall press force through the wheel to prevent slipping inside the pipe. This capability allows the robot to climb vertical pipes and adapt to various pipe diameters. Moreover, by combining CVT mechanisms, whose speed ratios between the driver and driven pulleys are passively adjusted by the position of the slider, the robot achieves independent and continuous speed control for each wheel. This enables it to navigate pipes with various geometries, such as straight–curved–straight pipes, using only one motor. Since active control of each wheel is not needed, the complexities of the robot controller can be significantly reduced. To validate the proposed mechanism, MATLAB simulations were conducted, and in-pipe driving experiments were executed. Both simulation and experimental results have shown that the robot can effectively navigate curved pipes with a maximum speed of 17.5 mm/s and a maximum traction force of 56.84 N

Time-Continuous Real-Time Trajectory Generation for Safe Autonomous Flight of a Quadrotor in Unknown Environment

In this paper, we present an efficient global and local replanning method for a quadrotor to complete a flight mission in a cluttered and unmapped environment. A minimum-snap global path planner generates a global trajectory that comprises some waypoints in a cluttered environment. When facing unexpected obstacles, our method modifies the global trajectory using geometrical planning and closed-form formulation for an analytical solution with 9th-order polynomial. The proposed method provides an analytical solution, not a numerical one, and it is computationally efficient without falling into a local minima problem. In a simulation, we show that the proposed method can fly a quadrotor faster than the numerical method in a cluttered environment. Furthermore, we show in experiments that the proposed method can provide safer and faster trajectory generation than the numerical method in a real environment

Square Root Iterated Kalman Filter for Bearing-Only SLAM

Abstract- This paper presents an undelayed solution to the bearing-only simultaneous localization and mapping problem (SLAM). We employ a square-root iterated Kalman filter for nonlinear state estimation. The proposed technique incorporates a modified Kalman update that is equivalent to a variable-step iterative Gauss-Newton method, and is numerically stable because it maintains a square-root decomposition of the covariance matrix. Although many existing bearingonly algorithms focus on proper initialization of landmark locations, our method allows for arbitrary initialization along the initial measurement ray without sacrificing map accuracy. This is desirable because we require only one filter and the state dimension of that filter need not include numerous temporary hypotheses. For this reason, the proposed algorithm is more computationally efficient than other methods. We demonstrate the feasibility of this approach in simulation and with experiments on mobile robots. Keywords- Bearing-only SLAM, Iterated Kalman Filter, Square root filte