scholarly journals Real-time quintic Hermite interpolation for robot trajectory execution

2020 ◽  
Vol 6 ◽  
pp. e304
Author(s):  
Morten Lind
Keyword(s):  
Real Time ◽  
Cycle Time ◽  
Real Time Control ◽  
Robot Controller ◽  
Time Control ◽  
Robot Trajectory ◽  
Robot Wrist ◽  
Trajectory Interpolation ◽  
High Level ◽  
Specific Implementation

This paper presents a real-time joint trajectory interpolation system for the purpose of frequency scaling the low cycle time of a robot controller, allowing a Python application to real-time control the robot at a moderate cycle time. Interpolation is based on quintic Hermite piece-wise splines. The splines are calculated in real-time, in a piecewise manner between the high-level, long cycle time trajectory points, while sampling of these splines at an appropriate, shorter cycle time for the real-time requirement of the lower-level system. The principle is usable in general, and the specific implementation presented is for control of the Panda robot from Franka Emika. Tracking delay analysis is presented based on a cosine trajectory. A simple test application has been implemented, demonstrating real-time feeding of a pre-calculated trajectory for cutting with a knife. Estimated forces on the robot wrist are recorded during cutting and presented in the paper.

scholarly journals Study on Application of Real-time Control Method for Controlling Position of Robots in the Given Time

2020 ◽  
Vol 3 (3) ◽  
pp. 461-471
Author(s):  
Tri Cong Phung
Keyword(s):  
Operating System ◽  
Real Time ◽  
Operating Systems ◽  
Control Method ◽  
Real Time Control ◽  
Real Time Operating System ◽  
The Real ◽  
Time Control ◽  
Robot Trajectory ◽  
The Given

Controlling accurately the position and velocity of robots in a given time is an important requirement in the industry. The open-source real-time operating systems not only have more advantages than the normal operating systems in both economy and flexibility but also meet the needs. This paper concentrates on building algorithms for controlling the robot trajectory in time using a modern real-time operating system called Linux-Xenomai. Firstly, the paper analyzes several advantages of the real-time operating system Linux-Xenomai comparing general operating systems and other real-time operating systems. Secondly, a real-time controller of a 5 degree-of-freedom (DOF) robot is built based on the real-time operating system Linux-Xenomai. After that, the paper proposes algorithms to test the ability of working in time of the robot. Finally, the real experiments are done to verify the proposed algorithms.

scholarly journals Software and Hardware Developments For a Mobile Manipulator Control

2008 ◽  
Vol 5 (1) ◽  
pp. 37
Author(s):  
F. Abdessemed ◽  
E. Monacelli
Keyword(s):  
Real Time ◽  
Mobile Manipulator ◽  
Real Time Control ◽  
Large Space ◽  
Time Control ◽  
Manipulator Arm ◽  
Software And Hardware ◽  
Free Environment ◽  
High Level ◽  
Manipulator Control

In this paper, we present the hardware and software architectures of an experimental real time control system of a mobile manipulator that performs tasks of manipulating objects in an environment of a large space. The mechanical architecture is a manipulator arm mounted on a mobile platform. In this work we show how one can implement an imbedded system, which includes the hardware and the software. The system makes use of a PC as the host and constitutes the high level layer. It is configured in such a way that it performs all the input-output interface operations; and is composed of different modules that constitute the software making up the required operations to be executed in a scheduling manner in order to meet the requirements of the real time control. In this paper, we also focus on the development of the generalized trajectory generation for the case of tasks where only one subsystem is considered to move and when the whole system is in permanent movement to achieve a particular task either in a free environment, or in presence of obstacles. 

OBJECT ORIENTED DESIGN, MODULAR ANALYSIS, AND FAULT-TOLERANCE OF REAL-TIME CONTROL SOFTWARE SYSTEMS

1996 ◽  
Vol 06 (03) ◽  
pp. 447-476 ◽  
Author(s):  
ANGELO PERKUSICH ◽  
MARIA L.B. PERKUSICH ◽  
SHI-KUO CHANG
Keyword(s):  
Petri Nets ◽  
Real Time ◽  
Software Systems ◽  
Real Time Control ◽  
Object Oriented Design ◽  
Time Control ◽  
Analysis Methodology ◽  
Modular Analysis ◽  
High Level ◽  
Time Systems

When specifying, designing and analyzing complex real-time systems, it is necessary to adopt a modular or compositional methodology. This methodology shall allow the designer the ability to verify local properties of individual modules or components in the system, and also shall allow the verification of the correct behavior of interacting components. The application of Petri nets for the modeling and verification of systems, at specification and design levels are well known. Despite the powerful structuring mechanisms available in the Petri nets theory for the construction of the model of complex systems, the designer is still likely to face the problem of state explosion, when analyzing and verifying large systems. In this work we introduce a modular analysis methodology for a kind of high level Petri nets named G-Nets.

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.

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