Kinematische Echtzeit-Regelung und auf vereinfachter Dynamik basierte Kraftregelung einer vierbeinigen Gehmaschine / Real-time kinematic control and on simplified dynamics based force control of a four-legged walking machine
The realization of walking machine covers various tasks like the mechanical construction, the software and hardware design as well as the development of suitable control strategies. In the available work this is accomplished including experimental testing for a four-legged walking machine.
The walking machine model consists of a central body and four identical, insect-like legs. To fulfill the requirement of the real time control, a rigid multibody system is selected for modelling. The appropriate motion equations are provided with the help of the method of the kinematic differentials. For the realization of the joint drives electrical direct current motor, incremental encoder and step-up gears are used. Accordingly the drive system is modelled in order to intend the demanded torque for the execution of the motion.
The description of the movement takes place via the trajectory of the center of gravity and of the swing leg. Statically stable running is guaranteed by the so-called coordination mechanisms between the center of gravity and the legs. This movement strategy represents however still open loop control, whereby the desired movement cannot be achieved at high speeds. Therefore the so-called kinematic position control is used, which considers only the kinematic of the controlled system. As consequence the requirements to the under-stored drive controllers are particularly high . This high requirement can be fulfilled by the use of the microcontroller LM629. In order to treat the reciprocal effect between the legs and the environment, the force control is used. This on simplified dynamics based force control can be used for the recognition of the leg collision.
For the implementation of the presented movement strategy and the position control as well as the force control a computer system with two PC/104 CPUs is used. On the two processors the operating system real-time Linux is used. The useability of the developed strategy is examined by experimental investigations. The co-ordination mechanisms are extended by the necessary stability reserve. By the overlay of the center of gravity movement with a sinusoidal oscillation the stability of the machine can be increased.
Advisor:Prof. Dr. rer. nat. Manfred Braun; Prof. em. Dr.-Ing. Martin Frik
School:Universität Duisburg-Essen, Standort Essen
Source Type:Master's Thesis
Keywords:energie maschinen und fertigungstechnik universitaet duisburg essen
Date of Publication:04/20/2006