In this paper, a kind of systems which occured in various problems in aerospace technology has been studied. Twin lift system is one of its special case. Because of the special structure of the systems, the controllability, observability, stability and existence of decentralized fixed modes of such systems can be tested on matrices of lower order. The same conclusion is true for circulant composite systems.
A near-optimal solution to the path-unconstrained timeoptimal trajectory planning problem is addressed in this paper. While traditional trajectory planning strategies are entirely based on kinematic considerations, manipulator dynamics are neglected altogether. This often results in mathematically tractable solutions which do not maximise the performance that manipulators might be capable of at any given time. The strategy presented in this work has two distinguishing features. First, the trajectory planning problem is reformulated as an optimal control problem which is in turn solved using Pontryagin's Maximum/Minimum Principle. This approach merges the traditional division of trajectory planning followed by trajectory tracking into one process. Secondly, the feedback form compensates for the dynamic approximation errors derived from the linearization approach taken and also the fundamental parameter uncertainty of the dynamic equations of motion. Results from simulations and an on-line implementation to a general purpose open-chain industrial manipulator, the CRS A251, confirm the validity of the approach and show that maximising the capabilities of the device can lead to an overall improvement in the manipulator time response of up to 25-30%.
Scheding, S, Dissanayake, G, Nebot, E & Durrant-Whyte, H 1997, 'Slip modelling and aided inertial navigation of an LHD', Proceedings - IEEE International Conference on Robotics and Automation, pp. 1904-1909.
This paper describes the theoretical development and experimental evaluation of a guidance system for an autonomous Load, Haul and Dump truck (LHD) for use in underground mining. The particular contributions of this paper are in designing the navigation system to be able to cope with vehicle slip in rough uneven terrain using information from an Inertial Navigation System (INS) and a bearing only laser. Results are presented using data obtained during field trials.