Advanced control designs for output tracking of hydrostatic transmissions

The work addresses simple but efficient model descriptions in a combination with advanced control and estimation approaches to achieve an accurate tracking of the desired trajectories. The proposed control designs are capable of fully exploiting the wide operation range of HSTs within the system configuration limits. A new trajectory planning scheme for the output tracking that uses both the primary and secondary control inputs was developed. Simple models or even purely data-driven models are envisaged and deployed to develop several advanced control approaches for HST systems

Volume 1 – Symposium: Tuesday, March 8

Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Components:Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Component

Causal Tracking Control of a Non-Minimum Phase HIL Transmission Test System

The automotive industry has long relied on testing powertrain components in real vehicles, which causes the development process to be slow and expensive. Therefore, hardware in the loop (HIL) testing techniques are increasingly being adopted to develop electronic control units (ECU) for engine and other components of a vehicle. In this thesis, HIL testing system is developed to provide a laboratory testing environment for continuously variable transmissions (CVTs). Two induction motors were utilized to emulate a real engine and vehicle. The engine and vehicle models, running in real-time, provide reference torque and speed signals for input and output dynamometers, respectively. To design torque and speed tracking controllers, linear models of the motor and drive systems were firstly identified from the test results. Feedforward controllers were then designed according to the inverse dynamics of the identified models. Because of the existence of unstable zeros in the model, design effort was focused on the stability and causality of the inverse process. Digital preview filters were formulated to approximate the stable inverse of unstable zeros as part of the feedforward controller. Normally, future information of input trajectory is required when implementing the digital preview filters, which makes the feedforward controller non-causal. Since the engine and vehicle model require current information to calculate the next output and no future value can be provided in advance, the application of non-causal digital controllers was limited. A novel method is proposed here to apply non-causal digital controllers causally. Robustness of the controllers is also considered when the two motors are coupled and the gear ratio between them was changed. The proposed coupled control method was tested and verified experimentally by using a manual gearbox before recommending its use for a CVT testing. A multifrequency test signal as well as simulation results of a whole vehicle model were used as torque and speed demand signals in the experiments. A HIL testing case was also presented. Frequency and time domain results showed the effectiveness of the method under both testing procedures to fully compensate for the dynamics of both actuators.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Bibliography of Lewis Research Center technical publications announced in 1993

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1993. All the publications were announced in the 1993 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

The Telecommunications and Data Acquisition Report

Reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA) are provided. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other agencies through NASA

Scientific applications of radio and radar tracking in the space program Conference proceedings

Radar and radio tracking applications in space progra

The Telecommunications and Data Acquisition Report

This quarterly publication provides archival reports on developments in programs in space communications, radio navigation, radio science, and ground-based radio and radar astronomy. It reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standardization activities at the Jet Propulsion Laboratory for space data and information systems

Geodetic Sciences

Space geodetic techniques, e.g., global navigation satellite systems (GNSS), Very Long Baseline Interferometry (VLBI), satellite gravimetry and altimetry, and GNSS Reflectometry & Radio Occultation, are capable of measuring small changes of the Earth�s shape, rotation, and gravity field, as well as mass changes in the Earth system with an unprecedented accuracy. This book is devoted to presenting recent results and development in space geodetic techniques and sciences, including GNSS, VLBI, gravimetry, geoid, geodetic atmosphere, geodetic geophysics and geodetic mass transport associated with the ocean, hydrology, cryosphere and solid-Earth. This book provides a good reference for geodetic techniques, engineers, scientists as well as user community

Bibliography of Lewis Research Center technical publications announced in 1992

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1992. All the publications were announced in the 1992 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses