Tobias Luksch

Development of complex robotic systems using the behavior-based control architecture iB2C

This paper presents a development methodology for complex robotic systems using the behavior-based control architecture iB2C (integrated Behavior-Based Control). It is shown how architectural principles support several behavior-based mechanisms, e.g. coordination mechanisms, behavior interaction, and hierarchical abstraction. Furthermore, design guidelines and structural patterns are presented which support the design and implementation process. The provided analysis tools and visualization techniques help to manage the complexity of large behavior-based networks. Finally, application examples are presented and a step by step description of constructing a behavior-based control structure for the outdoor robot Ravon is given.

An Activation-Based Behavior Control Architecture for Walking Machines

The high complexity of the mechanical system and the challenging task of walking itself makes the task of designing the control for legged robots a difficult one. Even if the implementation of parts of the desired functionality, such as posture control or basic swing/stance movement, can be solved by the use of classical engineering approaches, the control of the overall system tends to be very inflexible. In this paper we introduce a new method to combine aspects of classical robot control and behavior-based control. Inspired by the activation patterns in the brain and the spinal cord of animals, we propose a behavior network architecture using special signals such as activity or target rating to influence and coordinate the behaviors. We describe the general concept of a single behavior as well as their interaction within the network. This architecture is tested on the four-legged walking machine, BISAM, and experimental results are presented.

The Behaviour-Based Control Architecture iB2C for Complex Robotic Systems

This paper presents the behaviour-based control architecture iB2C (integrated Behaviour-Based Control) used for the development of complex robotic systems. The specification of behavioural components is described as well as the integration of behaviour coordination and hierarchical abstraction. It is considered how the design process can be supported by guidelines and by tools for development as well as analysis. Finally some application platforms are presented and a step by step description of building up a behaviour-based control structure for an outdoor robot is given.

Reactive reflex-based control for a four-legged walking machine

Abstract This paper presents methods and experiments of a reactive control architecture for a four-legged walking machine. Starting with a description of the existing control architecture we introduce the concepts of reflexes and behaviours as well as their integration into the system. The used reactive network and the development process is described in detail. The paper concludes with a description of various experiments.

Learning a reactive posture control on the four-legged walking machine BISAM

Presents methods and experiments of adaptive posture control for a four legged walking machine. Starting from the analysis of the implemented movement behaviour of BISAM we identify adequate tasks for adaptive control components and present adaptive posture control mechanisms for statically stable and dynamically stable movements. The reflex-based posture control is implemented via fuzzy control and reinforcement learning. The integration of the posture control in the control architecture is also described.

Fault-Tolerant Behavior-Based Motion Control for Offroad Navigation

Many tasks examined for robotic application like rescue missions or humanitarian demining require a robotic vehicle to navigate in unstructured natural terrain. This paper introduces a motion control for a four-wheeled offroad vehicle trying to tackle the problems arising. These include rough ground, steep slopes, wheel slippage, skidding and others that are difficult to grasp with a physical model and often impossible to acquire with sensory equipment. Therefore, a more reactive approach is chosen using a behavior-based architecture. This way a certain generalization in unknown environment is expected. The resulting behavior network is described and experiments performed in a simulation environment as well as in real world are presented. Additionally the performance of the utilized vehicle in case of mechanical or electronic defects is examined in simulation.

A Behaviour Network Concept for Controlling Walking Machines

The high complexity of the mechanical system and the difficult task of walking itself makes the task of designing the control for legged robots a diffcult one. Even if the implementation of parts of the desired functionality, like posture control or basic swing/stance movement, can be solved by the usage of classical engeneering approaches, the control of the overall system tends to be very unflexible. This paper introduces a new method to combine apects of classical robot control and behaviour based control. Inspired by the activation patterns in the brain and the spinal cord of animals we propose a behaviour network architecture using special signals like activity or target rating to influencce and coordinate the behaviours. The general concept of a single behaviour as well as their interaction within the network is described. This architecture is tested on the four-legged walking machine BISAM and experimental results are presented.

Biomimicing motion control of the WorkPartner robot

WorkPartner (WP), is the prototype of a mobile centaur‐like service robot designed to work interactively with humans in an outdoor environment. It moves using four wheeled legs and has a human‐like upper body. Tasks executed by the robot are similar to those that a human can do; the robot may replace or work together with people. Mobility is based on a hybrid system, which combines the benefits of both legs and wheels to provide good terrain negotiating capability and a large velocity range on variable ground. The robot is powered by a hybrid power system with electrical actuation and energy storage in the form of gasoline. The robot is equipped with a human‐like two‐hand manipulator. The long‐term goal is to develop an adaptive and learning robot, which can carry tools and work interactively with humans.

Controlling Human-like Locomotion of a Biped by a Biologically Motivated Approach

Controlling biped robots in a human-like way is still in the air in robotics. Due to the existing of shortcomings of technical control methods, researchers began to try to find help from biomechanics, neuroscience, human movement analysis and other biological fields. This paper presents a biologically inspired method of controlling the locomotion of biped robots based on the neurological and biomechanical research of human walking. The control concept looks inside of the human motion control to generate an efficient, robust control approach for bipedal dynamic walking. The framework of the control approach consists of a hierarchical architecture of control network, motor patterns and reflexes that works locally and distributed to exploit the inherent dynamics of of the system. In this paper, the approach is validated on a simulated anthropomorphic biped with 21 DoFs. Several locomotion like standing, walking initiation and cyclic walking have been deeply studied. This paper will study the biomechanical aspect and motion analysis of termination of gait and its application in a biped robot. The corresponding reflexes and motor patterns will be also introduced in this paper.

Biologically inspired compliant control of a monopod designed for highly dynamic applications

In this paper the compliant low level control of a biologically inspired control architecture suited for bipedal dynamic walking robots is presented. It consists of elastic mechanics, a low-level compliant joint controller and a hierarchical reflex-based control layer. The former is implemented on a DSP while the reflex network is located on a desktop PC. Thus, one is able to utilize distribution as a powerful means to guarantee low latency and scalability. The concept is tested on a prototype leg mounted on a vertical slider that is designed to perform cyclic squat jumps. Thus, a suited mechatronic setup that features highly dynamic actuators as well as energy storage capabilities is derived. Cyclical jumping is employed as a benchmark for the systems performance. Experimental results of the prototype setup as well as simulation runs are presented and compared to human squat jumping.