View Chapter

Chapter 40 — Mobility and Manipulation

Oliver Brock, Jaeheung Park and Marc Toussaint

Mobile manipulation requires the integration of methodologies from all aspects of robotics. Instead of tackling each aspect in isolation,mobilemanipulation research exploits their interdependence to solve challenging problems. As a result, novel views of long-standing problems emerge. In this chapter, we present these emerging views in the areas of grasping, control, motion generation, learning, and perception. All of these areas must address the shared challenges of high-dimensionality, uncertainty, and task variability. The section on grasping and manipulation describes a trend towards actively leveraging contact and physical and dynamic interactions between hand, object, and environment. Research in control addresses the challenges of appropriately coupling mobility and manipulation. The field of motion generation increasingly blurs the boundaries between control and planning, leading to task-consistent motion in high-dimensional configuration spaces, even in dynamic and partially unknown environments. A key challenge of learning formobilemanipulation consists of identifying the appropriate priors, and we survey recent learning approaches to perception, grasping, motion, and manipulation. Finally, a discussion of promising methods in perception shows how concepts and methods from navigation and active perception are applied.

Handling of a single object by multiple mobile robots based on caster-like dynamics

Author  Kazuhiro Kosuge

Video ID : 785

When multiple robots are utilized for the handling of an object, the slippage between wheels and the ground is the most serious challenge for coordinating the multiple robots. A control algorithm has been developed for mobile robots, which assumes they each possess caster-like dynamics.

Chapter 15 — Robot Learning

Jan Peters, Daniel D. Lee, Jens Kober, Duy Nguyen-Tuong, J. Andrew Bagnell and Stefan Schaal

Machine learning offers to robotics a framework and set of tools for the design of sophisticated and hard-to-engineer behaviors; conversely, the challenges of robotic problems provide both inspiration, impact, and validation for developments in robot learning. The relationship between disciplines has sufficient promise to be likened to that between physics and mathematics. In this chapter, we attempt to strengthen the links between the two research communities by providing a survey of work in robot learning for learning control and behavior generation in robots. We highlight both key challenges in robot learning as well as notable successes. We discuss how contributions tamed the complexity of the domain and study the role of algorithms, representations, and prior knowledge in achieving these successes. As a result, a particular focus of our chapter lies on model learning for control and robot reinforcement learning. We demonstrate how machine learning approaches may be profitably applied, and we note throughout open questions and the tremendous potential for future research.

Machine learning table tennis

Author  Jan Peters, Katharina Mülling, Jens Kober, Oliver Kroemer, Zhikun Wang

Video ID : 354

The video shows recent successful demonstrations of using machine learning for robot table tennis. The first part shows learning of motor primitives for forehand strikes by training a robot with a mixture of imitation and reinforcement learning. The second part shows how the robot can anticipate an opponent's intended targets based on both forehand and backhand primitives. The video illustrates Sect. 15.3.5 Policy Search of the Springer Handbook of Robotics, 2nd edn (2016). Reference: K. Mülling, J. Kober, O. Kroemer, J. Peters: Learning to select and generalize striking movements in robot table tennis, Int. J. Robot. Res. 32(3), 263-279 (2013)

Chapter 23 — Biomimetic Robots

Kyu-Jin Cho and Robert Wood

Biomimetic robot designs attempt to translate biological principles into engineered systems, replacing more classical engineering solutions in order to achieve a function observed in the natural system. This chapter will focus on mechanism design for bio-inspired robots that replicate key principles from nature with novel engineering solutions. The challenges of biomimetic design include developing a deep understanding of the relevant natural system and translating this understanding into engineering design rules. This often entails the development of novel fabrication and actuation to realize the biomimetic design.

This chapter consists of four sections. In Sect. 23.1, we will define what biomimetic design entails, and contrast biomimetic robots with bio-inspired robots. In Sect. 23.2, we will discuss the fundamental components for developing a biomimetic robot. In Sect. 23.3, we will review detailed biomimetic designs that have been developed for canonical robot locomotion behaviors including flapping-wing flight, jumping, crawling, wall climbing, and swimming. In Sect. 23.4, we will discuss the enabling technologies for these biomimetic designs including material and fabrication.

Robot dragonfly DelFly Explorer flies autonomously

Author  Christophe De Wagter, Sjoerd Tijmons, Bart D.W. Remes, Guido C.H.E. de Croon

Video ID : 402

The DelFly Explorer is the first flapping-wing micro air vehicle that is able to fly with complete autonomy in unknown environments. Weighing just 20 g, it is equipped with a 4 g onboard, stereo-vision system. The DelFly Explorer can perform an autonomous take-off, maintain its height, and avoid obstacles for as long as its battery lasts (~9 min). All sensing and processing is performed onboard, so no human or offboard computer is in the loop.

Chapter 11 — Robots with Flexible Elements

Alessandro De Luca and Wayne J. Book

Design issues, dynamic modeling, trajectory planning, and feedback control problems are presented for robot manipulators having components with mechanical flexibility, either concentrated at the joints or distributed along the links. The chapter is divided accordingly into two main parts. Similarities or differences between the two types of flexibility are pointed out wherever appropriate.

For robots with flexible joints, the dynamic model is derived in detail by following a Lagrangian approach and possible simplified versions are discussed. The problem of computing the nominal torques that produce a desired robot motion is then solved. Regulation and trajectory tracking tasks are addressed by means of linear and nonlinear feedback control designs.

For robots with flexible links, relevant factors that lead to the consideration of distributed flexibility are analyzed. Dynamic models are presented, based on the treatment of flexibility through lumped elements, transfer matrices, or assumed modes. Several specific issues are then highlighted, including the selection of sensors, the model order used for control design, and the generation of effective commands that reduce or eliminate residual vibrations in rest-to-rest maneuvers. Feedback control alternatives are finally discussed.

In each of the two parts of this chapter, a section is devoted to the illustration of the original references and to further readings on the subject.

State feedback response to impulse in presence of link flexibility

Author  Wayne Book

Video ID : 781

A laboratory gantry robot with a final flexible link is excited by an external impulse disturbance. The video shows the effective damping obtained using full state feedback control with an accurately tuned estimator. The reduction in settling time compared to PID joint control is dramatic. This is one of two coordinated videos, the other showing the same experiment under PID control. Reference: B. Post: Robust State Estimation for the Control of Flexible Robotic Manipulators, Dissertation, School of Mechanical Engineering, Georgia Institute of Technology, Atlanta (2013)

Chapter 15 — Robot Learning

Jan Peters, Daniel D. Lee, Jens Kober, Duy Nguyen-Tuong, J. Andrew Bagnell and Stefan Schaal

Machine learning offers to robotics a framework and set of tools for the design of sophisticated and hard-to-engineer behaviors; conversely, the challenges of robotic problems provide both inspiration, impact, and validation for developments in robot learning. The relationship between disciplines has sufficient promise to be likened to that between physics and mathematics. In this chapter, we attempt to strengthen the links between the two research communities by providing a survey of work in robot learning for learning control and behavior generation in robots. We highlight both key challenges in robot learning as well as notable successes. We discuss how contributions tamed the complexity of the domain and study the role of algorithms, representations, and prior knowledge in achieving these successes. As a result, a particular focus of our chapter lies on model learning for control and robot reinforcement learning. We demonstrate how machine learning approaches may be profitably applied, and we note throughout open questions and the tremendous potential for future research.

Inverse reinforcement

Author  Pieter Abbeel

Video ID : 353

This video shows a successful example of inverse reinforcement learning for acrobatic helicopter maneuvers. It illustrates apprenticeship learning algorithms, which leverage expert demonstrations to efficiently learn good controllers for tasks as demonstrated by an expert. The experimental results captured here include the first autonomous execution of a wide range of maneuvers and a complete airshow. The controllers perform as well as, and often even better than, the human expert pilot. The video illustrates a solution to the "Curse of Goal Specification" in Sect 15.3.6 Challenges in Robot Reinforcement Learning. Reference: P. Abbeel, A. Coates, A.Y. Ng: Autonomous helicopter aerobatics through apprenticeship learning, Int. J. Robot. Res. 29(13), 1608–1639 (2010)

Chapter 7 — Motion Planning

Lydia E. Kavraki and Steven M. LaValle

This chapter first provides a formulation of the geometric path planning problem in Sect. 7.2 and then introduces sampling-based planning in Sect. 7.3. Sampling-based planners are general techniques applicable to a wide set of problems and have been successful in dealing with hard planning instances. For specific, often simpler, planning instances, alternative approaches exist and are presented in Sect. 7.4. These approaches provide theoretical guarantees and for simple planning instances they outperform samplingbased planners. Section 7.5 considers problems that involve differential constraints, while Sect. 7.6 overviews several other extensions of the basic problem formulation and proposed solutions. Finally, Sect. 7.8 addresses some important andmore advanced topics related to motion planning.

Powder transfer task using demonstration-guided motion planning

Author  Ron Alterovitz

Video ID : 17

In unstructured environments such as people's homes, robots executing a task might need to avoid obstacles while satisfying the task's motion constraints. In this video, a robot completes a powder transfer task using demonstration-guided motion planning, an approach that combines an asymptotically-optimal sampling-based motion planner with a learned cost metric which encodes the task constraints.

Alpha puzzle

Author  Mark Moll

Video ID : 23

The alpha puzzle problem is a common benchmark scenario for motion planning. The puzzle consists of two intertwined twisted tubes. The objective is to separate the tubes, where one tube is considered a stationary obstacle and the other tube is the moving object (robot). Solving the problem is challenging because it contains a narrow passage in the configuration space. This plan was generated by a sampling-based motion planner implemented in the Open Motion Planning Library (OMPL).

Chapter 67 — Humanoids

Paul Fitzpatrick, Kensuke Harada, Charles C. Kemp, Yoshio Matsumoto, Kazuhito Yokoi and Eiichi Yoshida

Humanoid robots selectively immitate aspects of human form and behavior. Humanoids come in a variety of shapes and sizes, from complete human-size legged robots to isolated robotic heads with human-like sensing and expression. This chapter highlights significant humanoid platforms and achievements, and discusses some of the underlying goals behind this area of robotics. Humanoids tend to require the integration ofmany of the methods covered in detail within other chapters of this handbook, so this chapter focuses on distinctive aspects of humanoid robotics with liberal cross-referencing.

This chapter examines what motivates researchers to pursue humanoid robotics, and provides a taste of the evolution of this field over time. It summarizes work on legged humanoid locomotion, whole-body activities, and approaches to human–robot communication. It concludes with a brief discussion of factors that may influence the future of humanoid robots.

Footstep planning modeled as a whole-body, inverse-kinematic problem

Author  Eiichi Yoshida

Video ID : 596

An augmented-robot structure was introduced as "virtual" planar links attached to a foot that represents footsteps. This modeling makes it possible to solve the footstep planning as a problem of inverse kinematics, and also to determine the final whole-body configuration. After planning the footsteps, the dynamically-stable, whole-body motion including walking can be computed by using a dynamic pattern generator.

Chapter 76 — Evolutionary Robotics

Stefano Nolfi, Josh Bongard, Phil Husbands and Dario Floreano

Evolutionary Robotics is a method for automatically generating artificial brains and morphologies of autonomous robots. This approach is useful both for investigating the design space of robotic applications and for testing scientific hypotheses of biological mechanisms and processes. In this chapter we provide an overview of methods and results of Evolutionary Robotics with robots of different shapes, dimensions, and operation features. We consider both simulated and physical robots with special consideration to the transfer between the two worlds.

Evolved walking in octopod

Author  Phil Husbands

Video ID : 372

Evolved-walking behaviors on an octopod robot. Multiple gaits and obstacle avoidance can be observed. The behavior was evolved in a minimal simulation by Nick Jakobi at Sussex University and is successfully transferred to the real world as is evident from the video.

Chapter 38 — Grasping

Domenico Prattichizzo and Jeffrey C. Trinkle

This chapter introduces fundamental models of grasp analysis. The overall model is a coupling of models that define contact behavior with widely used models of rigid-body kinematics and dynamics. The contact model essentially boils down to the selection of components of contact force and moment that are transmitted through each contact. Mathematical properties of the complete model naturally give rise to five primary grasp types whose physical interpretations provide insight for grasp and manipulation planning.

After introducing the basic models and types of grasps, this chapter focuses on the most important grasp characteristic: complete restraint. A grasp with complete restraint prevents loss of contact and thus is very secure. Two primary restraint properties are form closure and force closure. A form closure grasp guarantees maintenance of contact as long as the links of the hand and the object are well-approximated as rigid and as long as the joint actuators are sufficiently strong. As will be seen, the primary difference between form closure and force closure grasps is the latter’s reliance on contact friction. This translates into requiring fewer contacts to achieve force closure than form closure.

The goal of this chapter is to give a thorough understanding of the all-important grasp properties of form and force closure. This will be done through detailed derivations of grasp models and discussions of illustrative examples. For an indepth historical perspective and a treasure-trove bibliography of papers addressing a wide range of topics in grasping, the reader is referred to [38.1].

Grasp analysis using the MATLAB toolbox SynGrasp

Author  Monica Malvezzi, Guido Gioioso, Gionata Salvietti, Domenico Prattichizzo

Video ID : 551

In this video a examples of few grasp analysis are documented and reported. The analysis is performed using SynGrasp, a MATLAB toolbox for grasp analysis. It provides a graphical user interface (GUI) which the user can adopt to easily load a hand and an object, and a series of functions that the user can assemble and modify to exploit all the toolbox features. The video shows how to use SynGrasp to model and analyze grasping, and, in particular it shows how users can select and load in the GUI a hand model, then choose an object and place it in the workspace selecting its position w.r.t. the hand. The grasp is obtained closing the hand from an initial configuration, which can be set by the users acting on hand joints. Once the grasp is defined, it can be analyzed by evaluating grasp quality measures available in the toolbox. Grasps can be described either using the provided grasp planner or directly defining contact points on the hand with the respective contact normal directions. SynGrasp can model both fully and underactuated robotic hands. An important role in grasp analysis, in particular with underactuated hands, is played by system compliance. SynGrasp can model the stiffness at contact points, at the joints or in the actuation system including transmission. A wide set of analytical functions, continuously increasing with new features and capabilities, has been developed to investigate the main grasp properties: controllable forces and object displacement, manipulability analysis, grasp stiffness and different measures of grasp quality. A set of functions for the graphical representation of the hand, the object, and the main analysis results is provided. The toolbox is freely available at http://syngrasp.dii.unisi.it.