**3.2.2 Manipulation**

It is now time for Rob to think about manipulation. He looks at his hands and starts thinking about the quasi-perfection found in this mechanism. He realizes that there is no other being in the animal kingdom that has reached similar levels of dexterity. His hands are the result of an evolutionary process of thousands of years which got them to the sophisticated level of manipulation the enjoy today. This process could have gone "hand-in-hand" with the evolution of higher cognitive abilities (Faisal et al., 2010). Considering human hands only, there is an even larger repertoire of motor actions that range from simple waving and hand signals to complex interactions such as manipulating a pen or spinning a top or shooting a marble (see Bullock & Dollar (2011) for a more detailed classification of human hand behaviors).

Rob is aware of the particular engineering challenge presented by interacting with objects in the real world. Trying to replicate as close as possible the human counterpart, current state of the art humanoid hands (Fig. 3) have four (Iwata et al., 2005; Liu et al., 2007) and five (Davis et al., 2008; Pons et al., 2004; Shadow Robot Company, 2003; Ueno & Oda, 2009) fingers, sometimes under-actuated through a set of tendons/cables as in the case of iCub's hands (Fig. 1(d)). However three-finger hands are also being used for manipulation, the most remarkable case being the work done at the Ishikawa-Oku Lab at the University of Tokyo (Ishikawa & Oku, 2011),Fig. 3(d). Through the use of high-speed cameras and actuators they have showed that it is possible to perform complex actions like throwing and catching or batting a ball, knoting a flexible rope with one manipulator, throwing and catching any type of objects with the same hand, or manipulating tools of different shapes.

The interaction between skin and bones in a human hand creates a dynamic balance between sensing and acting capabilities. By including skin-like materials into the design of robotic end-effectors it will be possible to re-create the optimized functionality of human hands. Skin that includes soft materials in its construction will add spring-damping properties to grasping behaviors. Accurate control of the hardware is transferred to the physical properties of the materials thus saving energy, time and resources. The future humanoid manipulator should be capable of interacting at a minimum with the same objects and displaying similar active and passive properties as human hands.

#### **3.3 Interim summary 1**

Rob realizes that the technology necessary to design and build a humanoid platform seems to be reaching a very mature level. In many cases the biggest obstacle is the lack of resources to put together state of the art sensors and actuators in the same project. We have seen remarkable innovations in the area of nano-materials which can help to overcome current obstacles in the acquisition of tactile, visual, and olfactory/taste information. At the same 8 Will-be-set-by-IN-TECH

interesting project will be the design of a decision making control that allows the agent to switch between the different motor behaviors. Switching between walking to crawling and vice versa, from walking to trotting or running and back. Those changes will need to be generated autonomously and dynamically as a response to the needs of the environment. The traditional way of programming a robot by following a set of rules in reaction to external stimuli does not work and will not work in dynamic, unconstrained environments. Rob is thinking about Asimo tripping over a step and hitting the floor with his face first. Rob knows that a more dynamic, autonomous and adaptive approach is needed for the future of

It is now time for Rob to think about manipulation. He looks at his hands and starts thinking about the quasi-perfection found in this mechanism. He realizes that there is no other being in the animal kingdom that has reached similar levels of dexterity. His hands are the result of an evolutionary process of thousands of years which got them to the sophisticated level of manipulation the enjoy today. This process could have gone "hand-in-hand" with the evolution of higher cognitive abilities (Faisal et al., 2010). Considering human hands only, there is an even larger repertoire of motor actions that range from simple waving and hand signals to complex interactions such as manipulating a pen or spinning a top or shooting a marble (see Bullock & Dollar (2011) for a more detailed classification of human hand

Rob is aware of the particular engineering challenge presented by interacting with objects in the real world. Trying to replicate as close as possible the human counterpart, current state of the art humanoid hands (Fig. 3) have four (Iwata et al., 2005; Liu et al., 2007) and five (Davis et al., 2008; Pons et al., 2004; Shadow Robot Company, 2003; Ueno & Oda, 2009) fingers, sometimes under-actuated through a set of tendons/cables as in the case of iCub's hands (Fig. 1(d)). However three-finger hands are also being used for manipulation, the most remarkable case being the work done at the Ishikawa-Oku Lab at the University of Tokyo (Ishikawa & Oku, 2011),Fig. 3(d). Through the use of high-speed cameras and actuators they have showed that it is possible to perform complex actions like throwing and catching or batting a ball, knoting a flexible rope with one manipulator, throwing and catching any type of objects with

The interaction between skin and bones in a human hand creates a dynamic balance between sensing and acting capabilities. By including skin-like materials into the design of robotic end-effectors it will be possible to re-create the optimized functionality of human hands. Skin that includes soft materials in its construction will add spring-damping properties to grasping behaviors. Accurate control of the hardware is transferred to the physical properties of the materials thus saving energy, time and resources. The future humanoid manipulator should be capable of interacting at a minimum with the same objects and displaying similar active

Rob realizes that the technology necessary to design and build a humanoid platform seems to be reaching a very mature level. In many cases the biggest obstacle is the lack of resources to put together state of the art sensors and actuators in the same project. We have seen remarkable innovations in the area of nano-materials which can help to overcome current obstacles in the acquisition of tactile, visual, and olfactory/taste information. At the same

the same hand, or manipulating tools of different shapes.

and passive properties as human hands.

**3.3 Interim summary 1**

his humanoid robot.

**3.2.2 Manipulation**

behaviors).

(c) ELU2's hand (d) Ishikawa-Oku's Lab manipulator

Fig. 3. Samples of different state of the art manipulators.

time, the exponential growth of computational power gives enough freedom to integrate all this information.

In terms of actuators, Rob is impressed by the results from the use of spring-damper components. Previous attempts to control this kind of materials gave many researchers (especially to those working with traditional control theory) several headaches. However current implementations for whole-body motion and manipulation have shown the feasibility of this approach, thanks most likely to the use of alternative methodologies, e.g. nonlinear dynamical systems.
