Norbert Sporer

On a new generation of torque controlled light-weight robots

The paper describes the recent design and development efforts in DLR Robotics Lab towards the second generation of light-weight robots. The design of the light weight mechanics, integrated sensors and electronics is outlined. The fully sensory joint, with motor and link position sensors as well as joint torque sensors enables the implementation of effective vibration damping and advanced control strategies for compliant manipulation. The mechatronic approach incorporates a tight collaboration between mechanics, electronics and controller design. The authors hope that important steps towards a new generation of service and personal robots have been achieved.

DLR's torque-controlled light weight robot III-are we reaching the technological limits now?

A third generation of torque-controlled light weight robots has been developed in DLRs robotics and mechatronics lab which is based on all the experiences that have been had with the first two generations. It aims at reaching the limits of what seems achievable with present day technologies not only with respect to light-weight, but also with respect to minimal power consumption and losses. One of the main gaps we tried to close in version III was the development of a new, robot-dedicated high energy motor designed with the best available techniques of concurrent engineering, and the renewed efforts to save weight in the links by using ultralight carbon fibres.

A mechatronics approach to the design of light-weight arms and multifingered hands

Describes design and development efforts in DLRs robotics lab towards a new generation of ultra-light weight robots with articulated hands. The design of fully sensorized joints with complete state feedback and the underlying mechanisms are outlined. The second light-weight arm generation is available now, as well as the second generation of a worldwide most highly integrated 4 finger-hand is available now. Thus we hope that important steps towards a new generation of service and personal robots have been achieved.

Space Robotics—DLR's Telerobotic Concepts, Lightweight Arms and Articulated Hands

The paper briefly outlines DLRs experience with real space robot missions (ROTEX and ETS VII). It then discusses forthcoming projects, e.g., free-flying systems in low or geostationary orbit and robot systems around the space station ISS, where the telerobotic system MARCO might represent a common baseline. Finally it describes our efforts in developing a new generation of “mechatronic” ultra-light weight arms with multifingered hands. The third arm generation is operable now (approaching present-day technical limits). In a similar way DLRs four-fingered hand II was a big step towards higher reliability and yet better performance. Artificial robonauts for space are a central goal now for the Europeans as well as for NASA, and the first verification tests of DLRs joint components are supposed to fly already end of 93 on the space station.

Dynamics of step-climbing with deformable wheels and applications for mobile Robotics

Wheeled-mobile robots operating in human environments typically encounter small steps. Surmounting steps is normally not considered when determining peak torque needs, yet it can be the maximum requirement. This work looks at the statics and dynamics of this situation to determine the necessary peak torque. It finds that using a dynamic model that includes the wheel elasticity is essential for properly representing a real-world tire. When torque is increased using a step function, energy is stored in the tire - higher tire elasticity eases climbing. Knowledge of this phenomenon could facilitate the use of smaller actuators. The model is numerically integrated and results are found to agree with experiment.

A new Generation of Light-Weight Robot Arms and Multifingered Hands

The keynote lecture describes recent design and development efforts in DLR’s robotics lab towards a new generation of ultra-light weight robots with articulated hands (Fig.1). The design of fully sensorized joints with complete state feedback and the underlying mechanisms are outlined. The second joint torque-controlled light-weight arm generation is available now [1], as well as the second generation of a highly integrated 4 finger-hand with 13 actuators and more than 100 sensors [2]. Thus we hope that important steps towards a new generation of service and personal robots have been achieved, with space robotics becoming a major driver due to the need for advanced “robonaut” technologies.