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Chapter 70 — Human-Robot Augmentation

Massimo Bergamasco and Hugh Herr

The development of robotic systems capable of sharing with humans the load of heavy tasks has been one of the primary objectives in robotics research. At present, in order to fulfil such an objective, a strong interest in the robotics community is collected by the so-called wearable robots, a class of robotics systems that are worn and directly controlled by the human operator. Wearable robots, together with powered orthoses that exploit robotic components and control strategies, can represent an immediate resource also for allowing humans to restore manipulation and/or walking functionalities.

The present chapter deals with wearable robotics systems capable of providing different levels of functional and/or operational augmentation to the human beings for specific functions or tasks. Prostheses, powered orthoses, and exoskeletons are described for upper limb, lower limb, and whole body structures. State-of-theart devices together with their functionalities and main components are presented for each class of wearable system. Critical design issues and open research aspects are reported.

Arm Light Exoskeleton (ALEx)

Author  Massimo Bergamasco

Video ID : 146

The video shows the Arm Light Exoskeleton (ALEx) and, in particular, its capability for tracking the operator's movements.

Chapter 68 — Human Motion Reconstruction

Katsu Yamane and Wataru Takano

This chapter presents a set of techniques for reconstructing and understanding human motions measured using current motion capture technologies. We first review modeling and computation techniques for obtaining motion and force information from human motion data (Sect. 68.2). Here we show that kinematics and dynamics algorithms for articulated rigid bodies can be applied to human motion data processing, with help from models based on knowledge in anatomy and physiology. We then describe methods for analyzing human motions so that robots can segment and categorize different behaviors and use them as the basis for human motion understanding and communication (Sect. 68.3). These methods are based on statistical techniques widely used in linguistics. The two fields share the common goal of converting continuous and noisy signal to discrete symbols, and therefore it is natural to apply similar techniques. Finally, we introduce some application examples of human motion and models ranging from simulated human control to humanoid robot motion synthesis.

Example of muscle tensions computed from motion-capture data

Author  Katsu Yamane

Video ID : 763

This video shows an example of muscle tensions computed from motion-capture data. The muscle color changes from yellow to red as the tension increases. The blue lines represent tendons.

Chapter 39 — Cooperative Manipulation

Fabrizio Caccavale and Masaru Uchiyama

This chapter is devoted to cooperative manipulation of a common object by means of two or more robotic arms. The chapter opens with a historical overview of the research on cooperativemanipulation, ranging from early 1970s to very recent years. Kinematics and dynamics of robotic arms cooperatively manipulating a tightly grasped rigid object are presented in depth. As for the kinematics and statics, the chosen approach is based on the socalled symmetric formulation; fundamentals of dynamics and reduced-order models for closed kinematic chains are discussed as well. A few special topics, such as the definition of geometrically meaningful cooperative task space variables, the problem of load distribution, and the definition of manipulability ellipsoids, are included to give the reader a complete picture ofmodeling and evaluation methodologies for cooperative manipulators. Then, the chapter presents the main strategies for controlling both the motion of the cooperative system and the interaction forces between the manipulators and the grasped object; in detail, fundamentals of hybrid force/position control, proportional–derivative (PD)-type force/position control schemes, feedback linearization techniques, and impedance control approaches are given. In the last section further reading on advanced topics related to control of cooperative robots is suggested; in detail, advanced nonlinear control strategies are briefly discussed (i. e., intelligent control approaches, synchronization control, decentralized control); also, fundamental results on modeling and control of cooperative systems possessing some degree of flexibility are briefly outlined.

Cooperative grasping and transportation of objects using multiple UAVs

Author  Daniel Mellinger, Michael Shomin, Nathan Michael, Vijay Kumar

Video ID : 66

This video shows experiments on cooperative grasping and transportation of objects using multiple UAVs equipped with grippers.

Chapter 41 — Active Manipulation for Perception

Anna Petrovskaya and Kaijen Hsiao

This chapter covers perceptual methods in which manipulation is an integral part of perception. These methods face special challenges due to data sparsity and high costs of sensing actions. However, they can also succeed where other perceptual methods fail, for example, in poor-visibility conditions or for learning the physical properties of a scene.

The chapter focuses on specialized methods that have been developed for object localization, inference, planning, recognition, and modeling in activemanipulation approaches.We concludewith a discussion of real-life applications and directions for future research.

Modeling articulated objects using active manipulation

Author  Juergen Strum

Video ID : 78

The video illustrates a mobile, manipulation robot that interacts with various articulated objects, such as a fridge and a dishwasher, in a kitchen environment. During interaction, the robot learns their kinematic properties such as the rotation axis and the configuration space. Knowing the kinematic model of these objects improves the performance of the robot and enables motion planning. Service robots operating in domestic environments are typically faced with a variety of objects they have to deal with to fulfill their tasks. Some of these objects are articulated such as cabinet doors and drawers, or room and garage doors. The ability to deal with such articulated objects is relevant for service robots, as, for example, they need to open doors when navigating between rooms and to open cabinets to pick up objects in fetch-and-carry applications. We developed a complete probabilistic framework that enables robots to learn the kinematic models of articulated objects from observations of their motion. We combine parametric and nonparametric models consistently and utilize the advantages of both methods. As a result of our approach, a robot can robustly operate articulated objects in unstructured environments. All software is available open-source (including documentation and tutorials) on http://www.ros.org/wiki/articulation.

Chapter 22 — Modular Robots

I-Ming Chen and Mark Yim

This chapter presents a discussion of modular robots from both an industrial and a research point of view. The chapter is divided into four sections, one focusing on existing reconfigurable modular manipulators typically in an industry setting (Sect. 22.2) and another focusing on self-reconfigurable modular robots typically in a research setting (Sect. 22.4). Both sections are sandwiched between the introduction and conclusion sections.

This chapter is focused on design issues. Rather than a survey of existing systems, it presents some of the existing systems in the context of a discussion of the issues and elements in industrial modular robotics and modular robotics research. The reader is encouraged to look at the references for further discussion on any of the presented topics.

4x4ht4a

Author  Hod Lipson

Video ID : 2

Self-reconfiguring cubes that reproduce a chain of cubes. Reference: V. Zykov, E. Mytilinaios, B. Adams, H. LipsonRobotics: Self-reproducing machines, Nature 435, 163-164 (2005); doi:10.1038/435163a

Chapter 41 — Active Manipulation for Perception

Anna Petrovskaya and Kaijen Hsiao

This chapter covers perceptual methods in which manipulation is an integral part of perception. These methods face special challenges due to data sparsity and high costs of sensing actions. However, they can also succeed where other perceptual methods fail, for example, in poor-visibility conditions or for learning the physical properties of a scene.

The chapter focuses on specialized methods that have been developed for object localization, inference, planning, recognition, and modeling in activemanipulation approaches.We concludewith a discussion of real-life applications and directions for future research.

Touch-based, door-handle localization and manipulation

Author  Anna Petrovskaya

Video ID : 723

The harmonic arm robot localizes the door handle by touching it. 3-DOF localization is performed in this video. Once the localization is complete, the robot is able to grasp and manipulate the handle. The mobile platform is teleoperated, whereas the robotic arm motions are autonomous. A 2-D model of the door and handle was constructed from hand measurements for this experiment.

Chapter 45 — World Modeling

Wolfram Burgard, Martial Hebert and Maren Bennewitz

In this chapter we describe popular ways to represent the environment of a mobile robot. For indoor environments, which are often stored using two-dimensional representations, we discuss occupancy grids, line maps, topologicalmaps, and landmark-based representations. Each of these techniques has its own advantages and disadvantages. Whilst occupancy grid maps allow for quick access and can efficiently be updated, line maps are more compact. Also landmark-basedmaps can efficiently be updated and maintained, however, they do not readily support navigation tasks such as path planning like topological representations do.

Additionally, we discuss approaches suited for outdoor terrain modeling. In outdoor environments, the flat-surface assumption underling many mapping techniques for indoor environments is no longer valid. A very popular approach in this context are elevation and variants maps, which store the surface of the terrain over a regularly spaced grid. Alternatives to such maps are point clouds, meshes, or three-dimensional grids, which provide a greater flexibility but have higher storage demands.

Learning navigation cost grids

Author  John Rebula

Video ID : 271

The video shows how the LittleDog robot of IHMC learns a terrain cost map based on several surface parameters. The map is then used for determining foot placements for the robot to enable it to traverse rough terrain.

Chapter 6 — Model Identification

John Hollerbach, Wisama Khalil and Maxime Gautier

This chapter discusses how to determine the kinematic parameters and the inertial parameters of robot manipulators. Both instances of model identification are cast into a common framework of least-squares parameter estimation, and are shown to have common numerical issues relating to the identifiability of parameters, adequacy of the measurement sets, and numerical robustness. These discussions are generic to any parameter estimation problem, and can be applied in other contexts.

For kinematic calibration, the main aim is to identify the geometric Denavit–Hartenberg (DH) parameters, although joint-based parameters relating to the sensing and transmission elements can also be identified. Endpoint sensing or endpoint constraints can provide equivalent calibration equations. By casting all calibration methods as closed-loop calibration, the calibration index categorizes methods in terms of how many equations per pose are generated.

Inertial parameters may be estimated through the execution of a trajectory while sensing one or more components of force/torque at a joint. Load estimation of a handheld object is simplest because of full mobility and full wrist force-torque sensing. For link inertial parameter estimation, restricted mobility of links nearer the base as well as sensing only the joint torque means that not all inertial parameters can be identified. Those that can be identified are those that affect joint torque, although they may appear in complicated linear combinations.

Calibration of ABB's IRB 120 industrial robot

Author  Ilian Bonev

Video ID : 422

The video depicts the process for the geometric calibration of the 6 DOF IRB 120. The calibration is based on the measurement of the position and the orientation of a tool using the laser tracking system from FARO. The video shows in sequence the steps in the acquisition of various configurations which can then be be employed using an algorithm similar to that of Sect. 6.2.

Chapter 56 — Robotics in Agriculture and Forestry

Marcel Bergerman, John Billingsley, John Reid and Eldert van Henten

Robotics for agriculture and forestry (A&F) represents the ultimate application of one of our society’s latest and most advanced innovations to its most ancient and important industries. Over the course of history, mechanization and automation increased crop output several orders of magnitude, enabling a geometric growth in population and an increase in quality of life across the globe. Rapid population growth and rising incomes in developing countries, however, require ever larger amounts of A&F output. This chapter addresses robotics for A&F in the form of case studies where robotics is being successfully applied to solve well-identified problems. With respect to plant crops, the focus is on the in-field or in-farm tasks necessary to guarantee a quality crop and, generally speaking, end at harvest time. In the livestock domain, the focus is on breeding and nurturing, exploiting, harvesting, and slaughtering and processing. The chapter is organized in four main sections. The first one explains the scope, in particular, what aspects of robotics for A&F are dealt with in the chapter. The second one discusses the challenges and opportunities associated with the application of robotics to A&F. The third section is the core of the chapter, presenting twenty case studies that showcase (mostly) mature applications of robotics in various agricultural and forestry domains. The case studies are not meant to be comprehensive but instead to give the reader a general overview of how robotics has been applied to A&F in the last 10 years. The fourth section concludes the chapter with a discussion on specific improvements to current technology and paths to commercialization.

An autonomous cucumber harvester

Author  Elder J. van Henten, Jochen Hemming, Bart A.J. van Tuijl, J.G. Kornet, Jan Meuleman, Jan Bontsema, Erik A. van Os

Video ID : 308

The video demonstrates an autonomous cucumber harvester developed at Wageningen University and Research Centre, Wageningen, The Netherlands. The machine consists of a mobile platform which runs on rails, which are commonly used in greenhouses in The Netherlands for the purpose of internal transport, but they are also used as a hot- water heating system for the greenhouse. Harvesting requires functional steps such as the detection and localization of the fruit and assessment of its ripeness. In the case of the cucumber harvester, the different reflection properties in the near infrared spectrum are exploited to detect green cucumbers in the green environment. Whether the cucumber was ready for harvest was identified based on an estimation of its weight. Since cucumbers consist 95% of water, the weight estimation was achieved by estimating the volume of each fruit. Stereo-vision principles were then used to locate the fruits to be harvested in the 3-D environment. For that purpose, the camera was shifted 50 mm on a linear slide and two images of the same scene were taken and processed. A Mitsubishi RV-E2 manipulator was used to steer the gripper-cutter mechanism to the fruit and transport the harvested fruit back to a storage crate. Collision-free motion planning based on the A* algorithm was used to steer the manipulator during the harvesting operation. The cutter consisted of a parallel gripper that grabbed the peduncle of the fruit, i.e., the stem segment that connects the fruit to the main stem of the plant. Then the action of a suction cup immobilized the fruit in the gripper. A special thermal cutting device was used to separate the fruit from the plant. The high temperature of the cutting device also prevented the potential transport of viruses from one plant to the other during the harvesting process. For each successful cucumber harvested, this machine needed 65.2 s on average. The average success rate was 74.4%. It was found to be a great advantage that the system was able to perform several harvest attempts on a single cucumber from different harvest positions of the robot. This improved the success rate considerably. Since not all attempts were successful, a cycle time of 124 s per harvested cucumber was measured under practical circumstances.

Chapter 30 — Sonar Sensing

Lindsay Kleeman and Roman Kuc

Sonar or ultrasonic sensing uses the propagation of acoustic energy at higher frequencies than normal hearing to extract information from the environment. This chapter presents the fundamentals and physics of sonar sensing for object localization, landmark measurement and classification in robotics applications. The source of sonar artifacts is explained and how they can be dealt with. Different ultrasonic transducer technologies are outlined with their main characteristics highlighted.

Sonar systems are described that range in sophistication from low-cost threshold-based ranging modules to multitransducer multipulse configurations with associated signal processing requirements capable of accurate range and bearing measurement, interference rejection, motion compensation, and target classification. Continuous-transmission frequency-modulated (CTFM) systems are introduced and their ability to improve target sensitivity in the presence of noise is discussed. Various sonar ring designs that provide rapid surrounding environmental coverage are described in conjunction with mapping results. Finally the chapter ends with a discussion of biomimetic sonar, which draws inspiration from animals such as bats and dolphins.

Side-looking multipulse sonar moving down cinder-block hallway

Author  Roman Kuc

Video ID : 303

Rather than producing a single TOF reading per emission, the multipulse sonar produces multiple spikes by quickly resetting the sonar-detector integrator, thereby producing a spike density related to the echo amplitude. A side-looking sonar scans a cinder-block wall containing a door and window jambs. The resulting spikes have been processed to differentiate the first cinder-block wall, the cider-block surface and localize the window and door jambs. The red circles indicate the initial TOF values and illustrate the additional echo waveform data produced by the multipulse sonar. Reference: R. Kuc: Recognizing retro-reflectors with an obliquely-oriented multi-point sonar and acoustic flow, Int. J. Robot. Res. 22(2), 129-145, (2003); doi:10.1177/0278364903022002004.