1,743,942 research outputs found
Redundant motor drive system
A drive system characterized by a base supporting a pair of pillars arranged in spaced parallelism, a shaft extended between and supported by the pillars for rotation about the longitudinal axis thereof, a worm gear affixed to the shaft and supported in coaxial relation therewith is described. A bearing housing of a sleeve like configuration is concentrically related to the shaft and is supported thereby for free rotation. A first and a second quiescent drive train, alternatively activatable, is provided for imparting rotation into said bearing housing. Each of the drive trains is characterized by a selectively energizable motor connected to a spur gear
Motor run-up system
A starting system is described for bringing a large synchronous motor up to speed to prevent large power line disturbances at the moment the motor is connected to the power line. The system includes (1) a digital counter which generates a count determined by the difference in frequency between the power line and a small current generated by the synchronous motor; (2) a latch which stores the count; and (3) a comparator which compares the stored count with a newly generated count to determine whether the synchronous motor is accelerating or decelerating. Signals generated by the counter and comparator control the current to a clutch that couples a starting motor to the large synchronous motor
Electronic motor control system Patent
Electronic circuit system for controlling electric motor spee
Motor Learning Mechanism on the Neuron Scale
Based on existing data, we wish to put forward a biological model of motor
system on the neuron scale. Then we indicate its implications in statistics and
learning. Specifically, neuron firing frequency and synaptic strength are
probability estimates in essence. And the lateral inhibition also has
statistical implications. From the standpoint of learning, dendritic
competition through retrograde messengers is the foundation of conditional
reflex and grandmother cell coding. And they are the kernel mechanisms of motor
learning and sensory motor integration respectively. Finally, we compare motor
system with sensory system. In short, we would like to bridge the gap between
molecule evidences and computational models.Comment: 8 pages, 4 figure
Maximum power operation of interacting molecular motors
We study the mechanical and thermodynamic properties of different traffic
models for kinesin which are relevant in biological and experimental contexts.
We find that motor-motor interactions play a fundamental role by enhancing the
thermodynamic efficiency at maximum power of the motors, as compared to the
non-interacting system, in a wide range of biologically compatible scenarios.
We furthermore consider the case where the motor-motor interaction directly
affects the internal chemical cycle and investigate the effect on the system
dynamics and thermodynamics.Comment: 19 pages, 22 figure
The design and development of a self-commutating stepper motor
The system discussed adopts a well established and space proven motor, the 'stepper-motor' and shows that with simple commutation techniques it can be operated as a brushless dc motor at high speeds
Apraxia and motor dysfunction in corticobasal syndrome
Background: Corticobasal syndrome (CBS) is characterized by multifaceted motor system dysfunction and cognitive disturbance; distinctive clinical features include limb apraxia and visuospatial dysfunction. Transcranial magnetic stimulation (TMS) has been used to study motor system dysfunction in CBS, but the relationship of TMS parameters to clinical features has not been studied. The present study explored several hypotheses; firstly, that limb apraxia may be partly due to visuospatial impairment in CBS. Secondly, that motor system dysfunction can be demonstrated in CBS, using threshold-tracking TMS, and is linked to limb apraxia. Finally, that atrophy of the primary motor cortex, studied using voxel-based morphometry analysis (VBM), is associated with motor system dysfunction and limb apraxia in CBS. Methods: Imitation of meaningful and meaningless hand gestures was graded to assess limb apraxia, while cognitive performance was assessed using the Addenbrooke's Cognitive Examination - Revised (ACE-R), with particular emphasis placed on the visuospatial subtask. Patients underwent TMS, to assess cortical function, and VBM. Results: In total, 17 patients with CBS (7 male, 10 female; mean age 64.4+/2 6.6 years) were studied and compared to 17 matched control subjects. Of the CBS patients, 23.5% had a relatively inexcitable motor cortex, with evidence of cortical dysfunction in the remaining 76.5% patients. Reduced resting motor threshold, and visuospatial performance, correlated with limb apraxia. Patients with a resting motor threshold <50% performed significantly worse on the visuospatial sub-task of the ACE-R than other CBS patients. Cortical function correlated with atrophy of the primary and pre-motor cortices, and the thalamus, while apraxia correlated with atrophy of the pre-motor and parietal cortices. Conclusions: Cortical dysfunction appears to underlie the core clinical features of CBS, and is associated with atrophy of the primary motor and pre-motor cortices, as well as the thalamus, while apraxia correlates with pre-motor and parietal atrophy
Induction motor controller using fuzzy logic
Induction Motor is widely used in general industry applications focusing on
production area. Induction motor speed control is becoming very important due to
increase the profit to the industries with increase efficiency, reliability and
performance of induction motor. Due to the problem facing in induction motor that
require complex mathematical model and varying parameters, Fuzzy Logic
Controller (FLC) is applied to overcome this problem. The FLC based on the
concepts of an artificial intelligence and attractive alternatives method to tackle the
problem of controller design for complex mathematical model of system. This
project used FLC Sugeno types. The purpose used FLC is to control speed and
increase the efficiency of IM. While, the conventional controller only works well for
linear system and their performances will decrease for nonlinear system. To make an
induction motor operates such as Direct Current (DC) motor, Field Oriented Control
(FOC) drives is applied for Induction Motor drive. FOC also offering a fast dynamic
response and a high precision ability for IM drive. This project is implemented using
Simulink Matlab. Based on the test results show the response of the speed curve
takes less time to settle and reach the desired value
Flueric-controller pneumatic stepping motor system
Nutating stepping motor consists of an output rotating gear and a nutating gear. A flueric logic circuit controls the nutating motor. The complete system constitutes a reliable, open loop actuator system with inherently high output stiffness, reasonable slewing speeds and small step size
Pain-motor integration in the primary motor cortex in Parkinson's disease
In Parkinson's disease (PD), the influence of chronic pain on motor features has never been investigated. We have recently designed a technique that combines nociceptive system activation by laser stimuli and primary motor cortex (M1) activation through transcranial magnetic stimulation (TMS), in a laser-paired associative stimulation design (Laser-PAS). In controls, Laser-PAS induces long-term changes in motor evoked potentials reflecting M1 long-term potentiation-like plasticity, arising from pain-motor integration
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