The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper presents a torque observer design, which can be used to accurately control and estimate impact torque of the automobile wheelchair. The controllers compensate a force for the plant to track up command speed when the plant's torque is accurately observed. This method of observer design is to combine an adaptive observer and a PI controller to accurately control the apparatus. The adaptive...
A purpose of this study is analyzing a human's controller to understand a mechanism of skill acquation processes for riding a unicycle. In order to analyze the controller, inputs which an operator gives to the unicycle and states of the unicycle are measured and a human-unicycle model as same as the experiment is derived. A weighting matrix to the state is obtained from the states, the inputs and...
Safe mobility of the disabled is one of the major reasons for the study of electric powered wheelchairs. To achieve absolute safety - where possible accident is not attributed to by the user's inability, the wheelchair should be as easy as possible to control in nearly every kind of environment. A reliable controller can only be designed from a reliable dynamic model. In this paper, consider a 3D...
This paper analyses the principle of synchronous belt fatigue life testing system, designs and realizes the control system with advanced controlling and detecting technology. We developed the mechanical system, Control System and windows-based software system for the Synchronous Belt Fatigue Life Testing System which working in Liaoyang mechanical belt factory very well.
The dynamics of spacecrafts with slewing payloads and flexible appendages are complicated, nonlinear, and coupling, which increase the difficulty of control. A new control scheme is presented for a type of flexible spacecrafts with slewing payloads. In the scheme, an adaptive fuzzy logic system (FLS) is designed to approximate the main dynamics of the plant, and an extended state observer (ESO) is...
An Unmanned bicycle stability adjusting mode by use of parallel mechanism is presented, and dynamics model of the unmanned bicycle with parallel mechanism adjusting stability is upbuilt in this paper. In order to increase stability and mobility, and carrying capability, the unmanned bicycle is controlled by a pedalling torque, a directional torque that generated using the steer adjustment, and by...
In this paper we propose a new fuzzy logic controller (FLC) for unicycle control. The FLC design integrates the linear quadratic regulator (LQR) and the gain-scheduling approach. By comparing FLC with the LQR designed around an operating point, the FLC coefficients can be easily tuned in a systematic way. The new FLC design aims at achieving three objectives: overcoming the difficulty in tuning the...
In the paper a method of vibroacoustic signal analysis based on meshing local plane ldquopinion tooth - gear toothrdquo concept is presented. The method is based on calculation of instantaneous energy density of the signal's envelope for the consecutive meshes and allows for acquiring information about the disturbances of the meshing process for particular teeth pairs. It permits the observation of...
A one hand drive wheelchair with power assist mechanism is developed. In this investigation, we propose a simple and useful manipulation torque detection method which yields wide detection areas with uniform distribution of stress. This method can be applied to a one hand drive wheelchair with complicated structure of manipulation mechanism with three rings. Moreover, even if the grasping position...
This paper presents a current-based wheel slip detecting method which can detect longitudinal wheel slip of a all-wheel driving vehicle running on road surface with different friction patches. A multi-mode slippage detection scheme is proposed to judge whether a wheel slippage occurs by detecting the change of the relevant wheel velocity and the change of the driving wheel armature current. A simple...
Active and passive approaches to accommodating moderate rover slip during coring, using a body mounted coring tool were studied. The work addresses the possibility of a 200 kg rover experiencing moderate slip such as 1 cm/minute while coring on a Martian slope using a body-mounted coring tool in a possible future Mars Sample Return mission. Rover slip while coring could be accommodated with passive...
As the Mars Exploration rovers have reaffirmed, some of the most interesting sites for scientists to explore on planetary surfaces lie in terrains that are currently inaccessible to state-of-the art rovers. We have been developing the Axel rover as a robotic platform to access steep and challenging terrain. We will summarize the recent mechanical upgrades since we introduced the tethered Axel concept...
Dawn is low-thrust interplanetary spacecraft enroute to the asteroids Vesta and Ceres in an effort to better understand the early creation of the solar system. After launch in September 2007, the spacecraft will flyby Mars in February 2009 before arriving at Vesta in summer of 2011 and Ceres in early 2015. Three solar electric ion-propulsion engines are used to provide the primary thrust for the Dawn...
This paper focused on discrete time and nearly time-optimal point to point navigation control of an autonomous power wheelchair. Nonlinear system dynamics is modeled and a discrete time PI type controller with disturbance input decoupler (DID) is designed. The linear and angular velocities are generated by a particular nearly time optimal command generator algorithm in which only one co-state equation...
This paper considers the optimal control problem for a wheeled car (robot) subject to inequality constraints which are induced by hardware. Before solving the optimal control problem, we propose an equality constraint to substitute the inequality constraints with a new technique, which is developed to design an optimal controller for tracking while characterizing the reasonable input torque. It is...
In this paper we introduce the Naval Research Laboratory's RESHAPE satellite control facility. This facility Provides a novel, practical bridge between theoretical control Studies and on-orbit performance of satellite systems in that test platform possesses three frictionless rotational degrees of freedom, an on-board data acquisition and digital control system, and a telemetry link to an off-board...
This paper presents practical information regarding the application of high-frequency (180-cycle) induction motors with low-resistance rotors to portable electric tools. In order to compete with existing tools it became necessary to increase the rotor speed above that of 60 cycles, and 180 cycles per second was adopted as commercially practical. Several advantages are shown. There is a smaller drop...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.