Abstract—The KUKA lightweight robot (LWR) provides
many unique features for robotic researchers. To give full ac-
cess to these features, a new interface was developed that gives
direct low-level real-time access to the KUKA robot controller
(KRC) at high rates of up to 1 kHz. On the other hand, all in-
dustrial-strength features, like teaching, motion script features,
fieldbus I/O and safety are provided. Using standard UDP
socket technology, the user is not limited to one specific runtime
system. This paper describes the capabilities of the interface,
the practical realization within the LWR control architecture
and first applications of the interface.
I. I
NTRODUCTION
The KUKA lightweight robot (LWR) (Figure1) is the lat-
est outcome of a bilateral research collaboration between
KUKA Roboter GmbH [1] and the Institute of Robotics and
Mechatronics at the German Aerospace Center (DLR) [2].
Due to its unique features like high payload ratio, program-
mable active compliance and torque sensor feedback, it en-
ables researchers and automation engineers to develop new
industrial and service robot applications. From the begin-
ning, one important aspect of the LWR product development
was to make features available from the KUKA controller
and its integrated scripting language (KUKA Robot Lan-
guage, KRL). This way, every industrial robot programmer
who is used to program standard industrial KUKA robots, is
able to program the LWR. KRL was extended to make avail-
able the LWR features, such as impedance control [3], which
is not available for standard robots. Also, the “all-in-a-box”
controller hardware was developed, so that power supply,
controller board and safety logic are in a common housing.
While this kind of approach fits the requirements of industry,
researchers have a more elaborate desire w.r.t. to such an
arm. To investigate the requirements of the research commu-
nity KUKA developed a questionnaire within the EC-funded
project BRICS – Best practice in robotics [4].
This paper is organized as follows: First the requirement
analysis will be presented that motivated the development of
the Fast Research Interface (FRI). Section III will explain the
FRI in more detail. The control system architecture and its
implementation are presented in sections IV and V, respec-
tively. First applications of the FRI are shown in section VI
before the paper is concluded in section VII.
Günter Schreiber is with KUKA Roboter GmbH, Augsburg, Germany
(e-mail: GuenterSchreiber@kuka-roboter.de )
Andreas Stemmer is with DLR, Institute of Robotics and Mechatronics,
Oberpfaffenhofen, Germany (e-mail: andreas.stemmer@dlr.de )
Rainer Bischoff is with KUKA Roboter GmbH, Augsburg, Germany
(e-mail: RainerBischoff@kuka-roboter.de )
Figure 1: KUKA Lightweight Robot (LWR) with KUKA Robot Controller
(KRC 2lr) and KUKA Control Panel (KCP).
II. R
EQUIREMENT
A
NALYSIS
A. The BRICS Project
The EC-funded project BRICS – Best practice in robotics
– provided the framework for the requirement analysis. The
prime objective of BRICS is to structure and formalize the
robot development process itself and to provide tools, mod-
els, and functional libraries, which allow reducing the devel-
opment time by a magnitude. BRICS is working together
with academic as well as industrial providers of robotics
“components” (hardware and software), to identify and
document best practices in the development of complex ro-
botics systems, to refactor (together) the existing components
in order to achieve a much higher level of reusability and
robustness, and to support the robot development process
with a structured tool chain and code repository.
The first target group of the BRICS project is the robotic
research community. BRICS aims at offering hardware with
a consistent set of harmonized, well-defined and docu-
mented, public APIs, and an integrated development envi-
ronment. BRICS will help researchers to design and make
operational complex robotic systems with minimal effort and
avoid so-called “from scratch developments”. BRICS in-
volves the community through questionnaires, workshops
and research camps.
The Fast Research Interface for the KUKA Lightweight Robot
Günter Schreiber, Andreas Stemmer, and Rainer Bischoff