Many successful robotic manipulator designs have been introduced. However, there remains the challenge of designing a manipulator that possesses the inherent safety characteristics necessary for human-centered robotics. In this paper, we present a new actuation approach that has the requisite characteristics for inherent safety while maintaining the performance expected of modern designs. By drastically reducing the effective impedance of the manipulator while maintaining high frequency torque capability, we show that the competing design requirements of performance and safety can be successfully integrated into a single manipulation system.

Summary form only given. There is a long history of people attempting to replicate human beings with machines that appear humanoid. The history of the idea of using robots which replicate human form is briefly outlined, and then the question of why one would want to replicate human forms is discussed from functional, psychological and social points of view. Although there is no reason a robot needs to look like a biological life form, there have always been aspects of robotics research which have followed the idea of simulating nature not only in function but also in appearance. In design there is a school of thought which maintains that in good design the form of an object is dictated by its function, this is known as "form follows function". This paper looks at the question of what advantages and disadvantages the human form has for robots.

The authors consider the design of robots that work in environments with obstacles. The environment and the obstacles are fixed and the robot consists of telescoping links with two degrees of freedom each, one revolute and one prismatic. The objective is to estimate the lowest number of telescoping links that the robot should have so that it can reach all the points in the workspace that are not inside the obstacles. Several estimates are derived for the planar case using different polygonal shapes for the obstacles and the outside boundary of the environment. An algorithm for finding a suboptimal estimate for the number of links in the plane is outlined. Some results for the three-dimensional case with polyhedral obstacles are obtained.>

The authors note a need to overcome the deficiencies inherent in conventional manipulator mechanisms. Joint torque controllability, optimal dynamic characteristics, motion redundancy, and fine manipulation ability are among the basic characteristics that would be desirable attributes of advanced robot systems. The paper discusses the limitations of current robot technology and describes the ongoing effort at Stanford University for the development of high-performance force-controlled robot systems to provide the advanced capabilities needed for carrying out dextrous manipulation tasks.>

The authors consider the design of series-parallel and in-parallel manipulators which are required to exert prescribed wrenches on the environment. The design methodology is based on statics because the resulting design equations are polynomials. The design equations for a series manipulator are obtained by taking appropriate components of the force and moment balance equations at each joint, at static equilibrium. For the in-parallel manipulators, the design equations are obtained from the static equilibrium equations of the coupler link only. The proposed ideas are a simple extension of the ideas of B. Roth (1988) to linkages which include helical, cylindric, and spherical joints.>

A study is made of the so-called slide motions between developable ruled surfaces with the line contact under spatial motion. In particular, the authors consider instantaneous time-based kinematics, which includes the contact speeds and rates of change along reference curves on the surfaces, the velocity, acceleration, and jerk of a reference point on the moving surface, and the constraints on the angular velocity and angular acceleration for maintaining line contact. The derived kinematic relationships can be applied to robotic path planning and actual motion calculations in the presence of a tactile sensor to measure the relative motion at the contact line.>

This paper is an extension to the 3-dimensional case of our previous work on planar motion with point contact [2]. Here we study the so called roll-slide spatial motions. Such motions occur whenever point contact between bodies is maintained under spatial motion. We consider instantaneous time-based kinematics and assume the presence of a tactile sensor to measure the relative motion at the point of contact. It is indicated how the derived kinematic relationships can be applied to sensor based robotic path planning.

Dexterous hands have the ability to grasp arbitrary parts and impart arbitrary motions to those objects. They also, in general, can be placed in special configurations where the grasp of an object is underconstrained or overconstrained. It is also possible to obtain special configurations where there are not enough or there are redundant degrees of freedom for moving an object, or where the hand mechanism is in a singular configuration. All of these special configurations are revealed through the examination of linear Jacobian matrix relationships describing a grasp. Formulations are presented for determining what useful manipulations can be performed, given these circumstances.