Modular embedded system for teaching real-time control

1994 ◽  
Author(s):  
R.J. Mitchell
Keyword(s):  
Embedded System ◽  
Real Time ◽  
Real Time Control ◽  
Time Control

scholarly journals Network-Oriented Real-Time Embedded System Considering Synchronous Joint Space Motion for an Omnidirectional Mobile Robot

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 317 ◽  
Author(s):  
Raimarius Delgado ◽  
Byoung Choi
Keyword(s):  
Mobile Robot ◽  
Embedded System ◽  
Real Time ◽  
Low Cost ◽  
Joint Space ◽  
Geometric Constraints ◽  
Real Time Control ◽  
Synchronization Mechanism ◽  
Omnidirectional Mobile Robot ◽  
Time Control

This paper proposes a real-time embedded system for joint space control of omnidirectional mobile robots. Actuators driving an omnidirectional mobile robot are connected in a line topology which requires synchronization to move simultaneously in translation and rotation. We employ EtherCAT, a real-time Ethernet network, to control servo controllers for the mobile robot. The first part of this study focuses on the design of a low-cost embedded system utilizing an open-source EtherCAT master. Although satisfying real-time constraints is critical, a desired trajectory on the center of the mobile robot should be decomposed into the joint space to drive the servo controllers. For the center of the robot, a convolution-based path planner and a corresponding joint space control algorithm are presented considering its physical limits. To avoid obstacles that introduce geometric constraints on the curved path, a trajectory generation algorithm considering high curvature turning points is adapted for an omnidirectional mobile robot. Tracking a high curvature path increases mathematical complexity, which requires precise synchronization between the actuators of the mobile robot. An improvement of the distributed clock—the synchronization mechanism of EtherCAT for slaves—is presented and applied to the joint controllers of the mobile robot. The local time of the EtherCAT master is dynamically adjusted according to the drift of the reference slave, which minimizes the synchronization error between each joint. Experiments are conducted on our own developed four-wheeled omnidirectional mobile robot. The experiment results confirm that the proposed system is very effective in real-time control applications for precise motion control of the robot even for tracking high curvature paths.

A Real Time Control Architecture for Continuously Managing Patients in a Care Unit

1995 ◽  
Vol 34 (05) ◽  
pp. 475-488
Author(s):  
B. Seroussi ◽  
J. F. Boisvieux ◽  
V. Morice
Keyword(s):  
Real Time ◽  
Linear Time ◽  
Treatment Plan ◽  
Control Architecture ◽  
Real Time Control ◽  
Time Representation ◽  
Time Control ◽  
Continuous Support ◽  
Definition Of ◽  
Computerized System

Abstract:The monitoring and treatment of patients in a care unit is a complex task in which even the most experienced clinicians can make errors. A hemato-oncology department in which patients undergo chemotherapy asked for a computerized system able to provide intelligent and continuous support in this task. One issue in building such a system is the definition of a control architecture able to manage, in real time, a treatment plan containing prescriptions and protocols in which temporal constraints are expressed in various ways, that is, which supervises the treatment, including controlling the timely execution of prescriptions and suggesting modifications to the plan according to the patient’s evolving condition. The system to solve these issues, called SEPIA, has to manage the dynamic, processes involved in patient care. Its role is to generate, in real time, commands for the patient’s care (execution of tests, administration of drugs) from a plan, and to monitor the patient’s state so that it may propose actions updating the plan. The necessity of an explicit time representation is shown. We propose using a linear time structure towards the past, with precise and absolute dates, open towards the future, and with imprecise and relative dates. Temporal relative scales are introduced to facilitate knowledge representation and access.

Real-time Control for Mobile Robot Considering Environmental Changes

2007 ◽  
Vol 73 (12) ◽  
pp. 1369-1374
Author(s):  
Hiromi SATO ◽  
Yuichiro MORIKUNI ◽  
Kiyotaka KATO
Keyword(s):  
Mobile Robot ◽  
Real Time ◽  
Environmental Changes ◽  
Real Time Control ◽  
Time Control

Using graphs to construct a math model of a microcontroller-based system for preset rate control of a flywheel motor to be used in high-dynamics spacecraft

2020 ◽  
pp. 126-134
Author(s):  
Vladimir V. NEKRASOV
Keyword(s):  
Real Time ◽  
Rotation Rate ◽  
Control Function ◽  
Real Time Control ◽  
Math Model ◽  
The Real ◽  
Time Control ◽  
Power Matrix ◽  
High Dynamics ◽  
Stated Problem

Developing a microcontroller-based system for controlling the flywheel motor of high-dynamics spacecraft using Russian-made parts and components made it possible to make statement of the problem of searching control function for a preset rotation rate of the flywheel rotor. This paper discusses one of the possible options for mathematical study of the stated problem, namely, application of structural analysis based on graph theory. Within the framework of the stated problem a graph was constructed for generating the new required rate, while in order to consider the stochastic case option the incidence and adjacency matrices were constructed. The stated problem was solved using a power matrix which transforms a set of contiguous matrices of the graph of admissible solution edge sequences, the real-time control function was found. Based on the results of this work, operational trials were run for the developed control function of the flywheel motor rotor rotation rate, a math model was constructed for the real-time control function, and conclusions were drawn about the feasibility of implementing the results of this study. Key words: Control function, graph, incidence matrix, adjacency matrix, power matrix, microcontroller control of the flywheel motor, highly dynamic spacecraft.

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